Application Setup

Introduction

In this exercise, we will create a semi-small graphical application for a water distribution company that provides water for various types of customers, including residential families, private businesses, government buildings, etc. The application uses a text-based database that processes records using collection classes. The records are saved in JSON files.

Practical LearningPractical Learning: Introducing the Application

  1. Start Microsoft Visual Studio
  2. In the Visual Studio 2026 dialog box, click Create a New Project
  3. In the Create a New Project dialog box, in the Languages combo box, select Visual Basic
  4. In the list of projects templates, click Windows Forms App
  5. Click Next
  6. Change the Project Name to StellarWaterPoint2
  7. Click Next
  8. In the Framework combo box, select the highest version: .NET 10.0 (Long Term Support)
  9. Click Create
  10. To create a folder, in the Solution Explorer, right-click StellarWaterPoint2 -> Add -> Folder
  11. Type Models as the name of the folder

The Main Form of the Application

Our application will use a central form acting as a switchboard from which other section-based forms can be accessed.

Practical LearningPractical Learning: Preparing the Main Form of the Application

  1. In the Solution Explorer, right-click Form1.vb and click Rename
  2. Type WaterDistribution (to get WaterDistribution.vb) and press Enter
  3. Read the message on the message box and click Yes
  4. Click the body of the form to make sure it is selected.
    In the Properties window, change the following characteristics:
    Text: Stellar Water Point
    StartPosition: CenterScreen
    MaximizeBox: False
  5. Right-click the body of the form and click View Code
  6. Change the document as follows: 
    Imports System.IO

Public Class WaterDistribution
    private sub WaterDistribution_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Directory.CreateDirectory("C:\Stellar Water Point2")
    End Sub
End Class

Water Meters

Introduction

The company of our application uses water meters to monitor the amount of water its customers consume. To start, the application needs a list of water meters that are available.

Practical LearningPractical Learning: Displaying Water Meters

  1. To create a class, in the Solution Explorer, right-click Models -> Add -> Class...
  2. In the Solution Explorer, right-click Models -> Add -> Class
  3. Replace the name with WaterMeter
  4. Click Add
  5. Change the code as follows: 
    Public Class WaterMeter
    Public Property WaterMeterId As Integer
    Public Property MeterNumber As String
    Public Property Make As String
    Public Property Model As String
    Public Property MeterSize As String
End Class

Displaying Water Meters

To let the user see a list of the water meters in the database, we will use a form equipped with a list view.

Practical LearningPractical Learning: Displaying Water Meters

  1. To create a form, in the Solution Explorer, right-click StellarWaterPoint2 -> Add -> Form (Windows Forms)...
  2. For the Name of the form, type WaterMetersCentral
  3. Click Add
  4. In the Toolbox, click the ListView button and click the form
  5. On the form, right-click the list view and click Edit Columns...
  6. Create the columns as follows:
    (Name) Text Width TextAlign
    colWaterMeterId Water Meter Id 150  
    colMeterNumber Meter # 150 Center
    ColMake Make 300  
    ColModel Model 150  
    ColMeterSize Meter Size 150  
  7. Click OK
  8. Position and resize the list view on the form as follows:

    Stellar Water Point - Water Meters

    Control (Name) Other Properties
    ListView List View LvwWaterMeters FullRowSelect: True
    GridLines: True
    View: Details
  9. Right-click the body of the form and click View Code
  10. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class Central
    Private Sub ShowWaterMeters()
        Dim StrWaterMeters As String = nothing
        Dim WaterMeters As List(Of WaterMeter) = New List(Of WaterMeter)
        Dim FileWaterMeters = "C:\Stellar Water Point2\WaterMeters.json"

        Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

        If FiWaterMeters.Exists = True Then
            Using TrWaterMeters As TextReader = New StreamReader(FiWaterMeters.FullName)
                StrWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
                WaterMeters = CType(JsonSerializer.Deserialize(StrWaterMeters, GetType(List(Of WaterMeter))), List(Of WaterMeter))

                LvwWaterMeters.Items.Clear()

                For Each Wm As WaterMeter In WaterMeters
                    Dim LviWaterMeter As ListViewItem = New ListViewItem(CStr(Wm.WaterMeterId))

                    LviWaterMeter.SubItems.Add(Wm.MeterNumber)
                    LviWaterMeter.SubItems.Add(Wm.Make)
                    LviWaterMeter.SubItems.Add(Wm.Model)
                    LviWaterMeter.SubItems.Add(Wm.MeterSize)

                    LvwWaterMeters.Items.Add(LviWaterMeter)
                Next
            End Using
        End If
    End Sub

    private sub Central_Load(sender As Object, e As EventArgs) handles  Central.Load Handles MyBase.Load
        ShowWaterMeters()
    End Sub
End Class
  11. In the Solution Explorer, double-click WaterDistribution.vb to display the main form of the application
  12. From the Toolbox, add a button to the form
  13. From the Properties window, change the characteristics of the button as follows:

    Stellar Water Point

    Control (Name) Text Font
    Button Button BtnWaterMeters &Water Meters... Times New Roman, 24pt, style=Bold
  14. Right-click the body of the form and click View Code
  15. Impliment an event as follows: 
    Imports System.IO

Public Class WaterDistribution
    private sub WaterDistribution_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Directory.CreateDirectory("C:\Stellar Water Point2")
    End Sub

    private sub BtnWaterMeters_Click(sender As Object, e As EventArgs) Handles BtnWaterMeters.Click
        Dim Listing = New WaterMetersCentral()

        Listing.Show()
    End Sub
End Class

A Water Meter Record

A water meter must be installed in the location where water is consumed. We will create a form that allows a user to create a new record for a water meter.

Practical LearningPractical Learning: Creating a Water Meter Record

  1. To create a form, in the Solution Explorer, right-click StellarWaterPoint2 -> Add -> Form (Windows Forms)...
  2. Type WaterMetersCreate
  3. Design the form as follows:

    Stellar Water Point - New Water Meter

    Control (Name) Text Other Properties
    Label Label   &Meter #:  
    MaskedTextBox Masked Text Box MtbMeterNumber   Masked: 000-000-000
    Modifiers: Public
    Label Label   &Water Meter Id:  
    TextBox Text Box TxtWaterMeterId   Modifiers: Public
    Label Label   M&ake:  
    TextBox Text Box TxtMake   Modifiers: Public
    Label Label   M&odel:  
    TextBox Text Box TxtModel   Modifiers: Public
    Label Label   Me&ter Size:  
    TextBox Text Box TxtMeterSize   Modifiers: Public
    Button Button BtnOK &OK DialogResult: OK
    Button Button BtnCancel &Cancel DialogResult: Cancel
  4. Using the Properties window, change some characteristics of the form as follows: 
    FormBorderStyle: FixedDialog
Text:            Stellar Water Point - Create Water Meter
StartPosition:   CenterScreen
AcceptButton:    BtnOK
CancelButton:    BtnCancel
  5. Right-click the body of the form and click View Code
  6. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class WaterMetersCreate
    Private Sub WaterMetersCreate_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim strWaterMeters = Nothing
        Dim WaterMeters = New List(Of WaterMeter)
        Dim FileWaterMeters = "C:\Stellar Water Point2\WaterMeters.json"

        Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

        Dim WaterMeterId = 0

        If FiWaterMeters.Exists = True Then
            Using TrWaterMeters As TextReader = New StreamReader(FiWaterMeters.FullName)
                strWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
                WaterMeters = CType(JsonSerializer.Deserialize(strWaterMeters, GetType(List(Of WaterMeter))), List(Of WaterMeter))

                For Each Meter As WaterMeter In waterMeters
                    WaterMeterId = Meter.WaterMeterId
                Next
            End Using
        End If

        TxtWaterMeterId.Text = CStr(WaterMeterId + 1)
    End Sub
End Class
  7. In the Solution Explorer, double-click WaterMetersCentral.vb
  8. From the Toolbox, add a button to the form below the list view
  9. Change the characteristics of the button as follows:

    Stellar Water Point - Water Meters

    Control (Name) Text
    ListView List View No Change No Change
    Button Button BtnNewWaterMeter &New Water Meter...
  10. Right-click anywhere on the form and click View Code
  11. Add code for the Click event of the button as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class WaterMetersCentral
    Private Sub ShowWaterMeters()
        . . .
    End Sub

    private sub Central_Load(sender As Object, e As EventArgs) handles  Central.Load Handles MyBase.Load
        ShowWaterMeters()
    End Sub

    Private Sub BtnNewWaterMeter_Click(sender As Object, e As EventArgs) Handles BtnNewWaterMeter.Click
        Dim Make = New WaterMetersCreate()

        If Make.ShowDialog() = DialogResult.OK Then
            If Make.MtbMeterNumber.Text.Replace("-", "").Trim() = "" Then
                MsgBox("You must type a meter number. " &
                       "Otherwise, the water meter cannot be set up.",
                       MsgBoxStyle.OkOnly, "Stellar Water Point")
                Exit Sub
            End If

            Dim StrWaterMeters As String = Nothing
            Dim WaterMeters As List(Of WaterMeter) = New List(Of WaterMeter)
            Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

            Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

            If FiWaterMeters.Exists = True Then
                StrWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
                WaterMeters = CType(JsonSerializer.Deserialize((StrWaterMeters, GetType(List(Of WaterMeter)), options:=New JsonSerializerOptions() With {.WriteIndented = True})
            End If

            Dim Meter As WaterMeter = New WaterMeter()

            If Make.TxtWaterMeterId.Text = "" Then
                Meter.WaterMeterId = 1
            Else
                Meter.WaterMeterId = CInt(Make.TxtWaterMeterId.Text)
            End If

            Meter.MeterNumber = Make.MtbMeterNumber.Text
            Meter.Make = Make.TxtMake.Text
            Meter.Model = Make.TxtModel.Text
            Meter.MeterSize = Make.TxtMeterSize.Text

            WaterMeters.Add(Meter)

            Dim Options As JsonSerializerOptions = New JsonSerializerOptions()
            Options.WriteIndented = True

            Dim jsWaterMeters = JsonSerializer.Serialize(WaterMeters, GetType(List(Of WaterMeter)), Options)
            File.WriteAllText(FiWaterMeters.FullName, jsWaterMeters)
        End If

        ShowWaterMeters()
    End Sub
End Class
  12. To execute the application, on the main menu, click Debug -> Start Without Debugging

    Stellar Water Point

  13. On the Central form, click the Water Meters button:

    Stellar Water Point - Water Meters

  14. Click the New Water Meter button:

    Stellar Water Point - New Water Meter

  15. Enter the value for each of the following records and click OK (or press Enter) for each:

    Meter # Make Model Meter Size
    392-494-572 Constance Technologies TG-4822 5/8 Inches
    938-705-869 Stan Wood 66-G 1 Inch
    588-279-663 Estellano NCF-226 3/4 Inches

    Stellar Water Point - Water Meters

  16. Close the forms and return to your programming environment

Water Meter Details

When the records of water meters have been created, sometimes, a user may want to view some details about a water meter. We are going to create such a form.

Practical LearningPractical Learning: Creating a Water Meter Record

  1. To create a form, in the Solution Explorer, right-click StellarWaterPoint2 -> Add -> Form (Windows Forms)...
  2. For the Name of the form, type WaterMetersDetails
  3. Press Enter
  4. Design the form as follows:

    Stellar Water Point - New Water Meter

    Control (Name) Text Enabled Modifiers Other Properties
    Label Label   &Meter #:      
    MaskedTextBox Masked Text Box MtbMeterNumber   False Public Masked: 000-000-000
    Button Button BtnFindWaterMeter &Find Water Meter      
    Label Label   Make:      
    TextBox Text Box TxtMake   False Public  
    Label Label   Model:      
    TextBox Text Box TxtModel   False Public  
    Label Label   Meter Size:      
    TextBox Text Box TxtMeterSize   False Public  
    Label Label   Water Meter Id:      
    TextBox Text Box TxtWaterMeterId   False Public  
    Button Button BtnClose &Close      
  5. Right-click anywhere on the form and click View Code
  6. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class WaterMetersDetails
    private sub BtnFindWaterMeter_Click(sender As Object, e As EventArgs) Handles BtnFindWaterMeter.Click
        If String.IsNullOrEmpty(MtbMeterNumber.Text) Then
            MsgBox("You must type a valid meter number, " &
                   "and then click the Find Water Meter button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrWaterMeters = Nothing
        Dim WaterMeters = New List(Of WaterMeter)
        Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

        Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

        If FiWaterMeters.Exists = True Then
            StrWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
            WaterMeters = CType(JsonSerializer.Deserialize(StrWaterMeters, GetType(List(Of WaterMeter))), List(Of WaterMeter))

            For Each Meter As WaterMeter In WaterMeters
                If Meter.MeterNumber = MtbMeterNumber.Text Then
                    TxtWaterMeterId.Text = Meter.WaterMeterId
                    TxtMake.Text = Meter.Make
                    TxtModel.Text = Meter.Model
                    TxtMeterSize.Text = Meter.MeterSize
                End If
            Next
        End If
    End Sub

    Private Sub BtnClose_Click(sender As Object, e As EventArgs) handles btnclose.click Handles BtnClose.Click
        Close()
    End Sub
End Class
  7. In the Solution Explorer, below the WaterMeters folder, double-click Central.vb to open its form
  8. From the Toolbox, add a button to the form below the list view and to the right of the New Water Meter button
  9. Change the characteristics of the button as follows:

    Stellar Water Point - Water Meters

    Control (Name) Other Properties
    ListView List View No Change No Change
    Button Button No Change No Change
    Button Button BtnViewWaterMeter &View Water Meter...
  10. Right-click the form and click View Code
  11. Add code for the Click event of the new button as follows: 
    Private Sub BtnWaterMeterDetails_Click(sender As Object, e As EventArgs) Handles BtnWaterMeterDetails.Click
    Dim Details As New WaterMetersDetails

    Details.Show()
End Sub
  12. To execute the application, on the main menu, click Debug -> Start Without Debugging

    Stellar Water Point

  13. On the Water Distribution form, click the Water Meters button
  14. On the Central form of water meters, click the View Water Meter button:

    Stellar Water Point - View Water Meter

  15. In the Meter # text, type 392-494-572
  16. Click the Find Water Button button:

    Stellar Water Point - View Water Meter

  17. Close the forms and return to your programming environment

Updating a Water Meter Record

One of the routine operations performed on a database is to change the details of a record. To support this operation for a water meter, we will create a form that can be used to update the information of a water meter.

Practical LearningPractical Learning: Updating a Water Meter

  1. To create a form, in the Solution Explorer, right-click StellarWaterPoint -> Add -> Form (Windows Forms)...
  2. For the Name of the file, type WaterMetersEditor as the name of the form
  3. Click Add
  4. Design the form as follows:

    Stellar Water Point - New Water Meter

    Control (Name) Text Enabled Other Properties
    Label Label   &Meter #:    
    MaskedTextBox Masked Text Box MtbMeterNumber   False Masked: 000-000-000
    Button Button BtnFindWaterMeter &Find Water Meter    
    Label Label   Make:    
    TextBox Text Box TxtMake   False  
    Label Label   Model:    
    TextBox Text Box TxtModel   False  
    Label Label   Meter Size:    
    TextBox Text Box TxtMeterSize   False  
    Button Button BtnUpdateWaterMeter &Update Water Meter    
    Button Button BtnClose &Close    
  5. Right-click somewhere on the form and click View Code
  6. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class WaterMetersEditor

    private sub BtnFindWaterMeter_Click(sender As Object, e As EventArgs) Handles BtnFindWaterMeter.Click
        If String.IsNullOrEmpty(MtbMeterNumber.Text) Then
            MsgBox("You must type a valid meter number, " &
                   "and then click the Find Water Meter button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrWaterMeters = Nothing
        Dim WaterMeters = New List(Of WaterMeter)
        Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

        Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

        If FiWaterMeters.Exists = True Then
            StrWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
            WaterMeters = CType(JsonSerializer.Deserialize(StrWaterMeters, GetType(List(Of WaterMeter))), List(Of WaterMeter))

            For Each Meter As WaterMeter In WaterMeters
                If Meter.MeterNumber = MtbMeterNumber.Text Then
                    TxtWaterMeterId.Text = Meter.WaterMeterId
                    TxtMake.Text = Meter.Make
                    TxtModel.Text = Meter.Model
                    TxtMeterSize.Text = Meter.MeterSize
                End If
            Next
        End If
    End Sub

    Private Sub BtnUpdateWaterMeter_Click(sender As Object, e As EventArgs) Handles BtnUpdateWaterMeter.Click
        If String.IsNullOrEmpty(MtbMeterNumber.Text) Then
            MsgBox("You must type a valid meter number, " &
                   "and then click the Find Water Meter button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim strWaterMeters = Nothing
        Dim WaterMeters = New List(Of WaterMeter)
        Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

        Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

        If FiWaterMeters.Exists = True Then
            strWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
            WaterMeters = CType(JsonSerializer.Deserialize(strWaterMeters, GetType(List(Of WaterMeter))), List(Of WaterMeter))

            Dim meter = WaterMeters.Find(Function(Mtr) Mtr.MeterNumber = MtbMeterNumber.Text)

            If Not meter Is Nothing Then
                meter.WaterMeterId = CInt(TxtWaterMeterId.Text)
                meter.Make = TxtMake.Text
                meter.Model = TxtModel.Text
                meter.MeterSize = TxtMeterSize.Text

                Dim options = New JsonSerializerOptions()
                options.WriteIndented = True

                Dim jsWaterMeters = JsonSerializer.Serialize(WaterMeters, GetType(List(Of WaterMeter)), options)
                File.WriteAllText(FiWaterMeters.FullName, jsWaterMeters)
            End If
        End If

        Close()
    End Sub

    Private Sub BtnClose_Click(sender As Object, e As EventArgs) Handles BtnClose.Click
        Close()
    End Sub
End Class
  7. In the Solution Explorer, double-click WaterMetersCentral.vb
  8. From the Toolbox, add a button to the form below the list view and on the right side of the View Water Meter button
  9. Change the characteristics of the button as follows:

    Stellar Water Point - Water Meters

    Control (Name) Other Properties
    ListView List View No Change No Change
    Button Button No Change No Change
    Button Button No Change No Change
    Button Button BtnEditWaterMeter &Edit Water Meter...
  10. Right-click the form and click View Code
  11. Add a procedure as follows: 
    Private Sub BtnWaterMeterEitor_Click(sender As Object, e As EventArgs) Handles BtnWaterMeterEditor.Click
    Dim Editor As New WaterMetersEditor

    Editor.ShowDialog()

    ShowWaterMeters()
End Sub
  12. To execute the application, on the main menu, click Debug -> Start Without Debugging:

    Stellar Water Point

  13. On the Central form, click the Water Meters button:

    Stellar Water Point - Water Meters

  14. Click the Update Water Meter button:

    Stellar Water Point - Water Meter Editor

  15. In the Meter # text, type 938-705-869
  16. Click the Find button

    Stellar Water Point - Water Meter Editor

  17. Change the values as follows:
    Make: Stanford Trend
    Model: 266G
    Meter Size: 1 1/2 Inches

    Stellar Water Point - Water Meter Editor

  18. Click the Update button:

    Stellar Water Point - Water Meters

  19. Close the forms and return to your programming environment

Removing a Water Meter from the Database

If a record of a water meter is not necessary anymore, a user can be asked to delete such a record. We are going to create a form for such an operation.

Practical LearningPractical Learning: Deleting a Water Meter Record

  1. To create a form, in the Solution Explorer, right-click StellarWaterPoint2 -> Add -> Form(Windows Forms)...
  2. In the Name text box, replace the string with WaterMetersDelete as the name of the form
  3. Press Enter
  4. Design the form as follows:

    Stellar Water Point - Water Meter Deletion

    Control (Name) Text Enabled Other Properties
    Label Label   &Meter #:    
    MaskedTextBox Masked Text Box MtbMeterNumber   False Masked: 000-000-000
    Label Label   Make:    
    TextBox Text Box TxtMake   False  
    Label Label   Model:    
    TextBox Text Box TxtModel   False  
    Label Label   Meter Size:    
    TextBox Text Box TxtMeterSize   False  
    Button Button BtnClose &Close    
  5. Right-click anywhere on the form and click View Code
  6. Change the document as tollows: 
    Imports System.IO
Imports System.Text.Json

Public Class WaterMetersDelete
    private sub BtnFindWaterMeter_Click(sender As Object, e As EventArgs) Handles BtnFindWaterMeter.Click
        If String.IsNullOrEmpty(MtbMeterNumber.Text) Then
            MsgBox("You must type a valid meter number, " &
                   "and then click the Find Water Meter button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrWaterMeters = Nothing
        Dim WaterMeters = New List(Of WaterMeter)
        Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

        Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

        If FiWaterMeters.Exists = True Then
            StrWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
            WaterMeters = CType(JsonSerializer.Deserialize(StrWaterMeters, GetType(List(Of WaterMeter))), List(Of WaterMeter))

            For Each Meter As WaterMeter In WaterMeters
                If Meter.MeterNumber = MtbMeterNumber.Text Then
                    TxtWaterMeterId.Text = Meter.WaterMeterId
                    TxtMake.Text = Meter.Make
                    TxtModel.Text = Meter.Model
                    TxtMeterSize.Text = Meter.MeterSize
                End If
            Next
        End If
    End Sub

    Private Sub BtnDeleteWaterMeter_Click(sender As Object, e As EventArgs) Handles BtnDeleteWaterMeter.Click
        If MtbMeterNumber.Text.Replace("-", "").Trim().Equals(Nothing) Then
            MsgBox("You must type a valid meter number, " &
                   "and then click the Find Water Meter button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrWaterMeters = Nothing
        Dim WaterMeters = New List(Of WaterMeter)
        Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

        Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

        If FiWaterMeters.Exists = True Then
            StrWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
            WaterMeters = CType(JsonSerializer.Deserialize(StrWaterMeters, GetType(List(Of WaterMeter))), List(Of WaterMeter))

            Dim Meter = WaterMeters.Find(Function(Mtr) Mtr.MeterNumber = MtbMeterNumber.Text)

            If Not Meter Is Nothing Then
                If MsgBox("Are you sure you want to delete this water meter " &
                          "(you cannot undo the action)?",
                          MsgBoxStyle.YesNoCancel, "Stellar Water Point") = MsgBoxResult.Yes Then
                    WaterMeters.Remove(Meter)

                    Dim options = New JsonSerializerOptions()
                    options.WriteIndented = True

                    Dim jsWaterMeters = JsonSerializer.Serialize(WaterMeters, GetType(List(Of WaterMeter)), options)
                    File.WriteAllText(FiWaterMeters.FullName, jsWaterMeters)

                    MsgBox("The water meter has been removed from our database.",
                           MsgBoxStyle.OkOnly, "Stellar Water Point")
                End If
            End If
        End If

        Close()
    End Sub

    Private Sub BtnClose_Click(sender As Object, e As EventArgs) Handles BtnClose.Click
        Close()
    End Sub
End Class
  7. In the Solution Explorer, double-click WaterMetersCentral.vb
  8. From the Toolbox, add two buttons to the form below the list view and on the right side of the Edit Water Meter button
  9. Change the characteristics of the buttons as follows:

    Stellar Water Point - Water Meters

    Control (Name) Text Anchor
    ListView List View LvwWaterMeters   Top, Bottom, Left, Right
    Button Button BtnNewWaterMeter &New Water Meter... Bottom, Right
    Button Button BtnViewWaterMeter &View Water Meter... Bottom, Right
    Button Button BtnEditWaterMeter &Edit Water Meter... Bottom, Right
    Button Button BtnDeleteWateMeter &Delete Water Meter... Bottom, Right
    Button Button BtnClose &Close Bottom, Right
  10. On the form, double-click the Delete Water Meter button
  11. Return to the Central form of the water meters and double-click the Close button
  12. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class WaterMetersCentral
    Private Sub ShowWaterMeters()
        Dim StrWaterMeters As String = String.Empty
        Dim WaterMeters As List(Of WaterMeter) = New List(Of WaterMeter)
        Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

        Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

        If FiWaterMeters.Exists = True Then
            Using TrWaterMeters As TextReader = New StreamReader(FiWaterMeters.FullName)
                StrWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
                WaterMeters = CType(JsonSerializer.Deserialize(StrWaterMeters, GetType(List(Of WaterMeter))), List(Of WaterMeter))

                LvwWaterMeters.Items.Clear()

                For Each Wm As WaterMeter In WaterMeters
                    Dim LviWaterMeter As ListViewItem = New ListViewItem(Wm.WaterMeterId)

                    LviWaterMeter.SubItems.Add(Wm.MeterNumber)
                    LviWaterMeter.SubItems.Add(Wm.Make)
                    LviWaterMeter.SubItems.Add(Wm.Model)
                    LviWaterMeter.SubItems.Add(Wm.MeterSize)

                    LvwWaterMeters.Items.Add(LviWaterMeter)
                Next
            End Using
        End If
    End Sub

    private sub Central_Load(sender As Object, e As EventArgs) handles  Central.Load Handles MyBase.Load
        ShowWaterMeters()
    End Sub

    Private Sub BtnNewWaterMeter_Click(sender As Object, e As EventArgs) Handles BtnNewWaterMeter.Click
        Dim Make = New WaterMetersCreate

        If Make.ShowDialog = DialogResult.OK Then
            If Make.MtbMeterNumber.Text.Replace("-", "").Trim = "" Then
                MsgBox("You must type a meter number. " &
                       "Otherwise, the water meter cannot be set up.",
                       MsgBoxStyle.OkOnly, "Stellar Water Point")
                Exit Sub
            End If

            Dim StrWaterMeters As String = Nothing
            Dim WaterMeters = New List(Of WaterMeter)
            Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

            Dim FiWaterMeters = New FileInfo(FileWaterMeters)

            If FiWaterMeters.Exists = True Then
                StrWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
                WaterMeters = JsonSerializer.Deserialize(StrWaterMeters, GetType(List(Of WaterMeter)))
            End If

            Dim Meter = New WaterMeter

            If Make.TxtWaterMeterId.Text = "" Then
                Meter.WaterMeterId = 1
            Else
                Meter.WaterMeterId = CInt(Make.TxtWaterMeterId.Text)
            End If

            Meter.MeterNumber = Make.MtbMeterNumber.Text
            Meter.Make = Make.TxtMake.Text
            Meter.Model = Make.TxtModel.Text
            Meter.MeterSize = Make.TxtMeterSize.Text

            WaterMeters.Add(Meter)

            Dim Options = New JsonSerializerOptions
            Options.WriteIndented = True

            Dim jsWaterMeters = JsonSerializer.Serialize(WaterMeters, GetType(List(Of WaterMeter)), Options)
            File.WriteAllText(FiWaterMeters.FullName, jsWaterMeters)
        End If

        ShowWaterMeters()
    End Sub

    Private Sub BtnWaterMeterDetails_Click(sender As Object, e As EventArgs) Handles BtnWaterMeterDetails.Click
        Dim Details As New WaterMetersDetails

        Details.Show()
    End Sub

    Private Sub BtnWaterMeterEitor_Click(sender As Object, e As EventArgs) Handles BtnWaterMeterEditor.Click
        Dim Editor As New WaterMetersEditor

        Editor.ShowDialog()

        ShowWaterMeters()
    End Sub

    Private Sub BtnDeleteWaterMeter_Click(sender As Object, e As EventArgs) Handles BtnDeleteWaterMeter.Click
        Dim Delete As New WaterMetersDelete

        Delete.ShowDialog()

        ShowWaterMeters()
    End Sub

    Private Sub BtnClose_Click(sender As Object, e As EventArgs) Handles BtnClose.Click
        Close()
    End Sub
End Class
  13. To execute the application, on the main menu, click Debug -> Start Without Debugging:

    Stellar Water Point - Water Meters

  14. On the Central form, click the Water Meters button:

    Stellar Water Point - Water Meters

  15. On the Central form of the water meters, click the Delete Water Meter button:

    Stellar Water Point - Water Meter Deletion

  16. In the Meter # text, type 588-279-663
  17. Click the Find button:

    Stellar Water Point - Water Meter Deletion

  18. Click the Delete button:

    Stellar Water Point - Water Meter Deletion

  19. Read the text on the message box and click Yes
  20. Read the other message box and click OK
  21. In the same way, delete the other two records
  22. Close the forms and return to your programming environment

Customers

Introduction

For a water distribution company, a customer is a person, a business, or any entity that consumes water. At a minimum, a computer must keep a list of entities that use its business.

Accounts Types

To help the company manage customers accounts and especially for accounting purpose, every customer account will be identified with its type of account. This is because the company deals with regular residences, businesses, government entitites, etc. To assist with this, we will create a class for accounts types.

Practical LearningPractical Learning: Introducing Accounts Types

  1. To create a class, in the Solution Explorer, right-click Models -> Add -> Class...
  2. In the Solution Explorer, right-click Models -> Add -> Class
  3. Set the file Name to AccountType
  4. Click Add
  5. Change the code as follows: 
    Public Class AccountType
    Public Property AccountTypeId As Integer
    Public Property TypeCode As String
    Public Property TypeDecription As String
End Class
  6. In the Solution Explorer, right-click WaterDistribution.vb and click View Code
  7. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class WaterDistribution
    Private Sub CreateWaterMeters()
        Dim WaterMeters = New List(Of WaterMeter) From {
            New WaterMeter With {.WaterMeterId = 1, .MeterNumber = "392-494-572", .Make = "Constance Technologies", .Model = "TG-4822", .MeterSize = "5/8 Inches"},
            New WaterMeter With {.WaterMeterId = 2, .MeterNumber = "938-725-869", .Make = "Stanford Trend", .Model = "266G", .MeterSize = "1 1/2 Inches"},
            New WaterMeter With {.WaterMeterId = 3, .MeterNumber = "588-279-663", .Make = "Estellano", .Model = "NCF-226", .MeterSize = "4 Inches"},
            New WaterMeter With {.WaterMeterId = 4, .MeterNumber = "186-962-805", .Make = "Lansome", .Model = "2800", .MeterSize = "1 1/2 Inches"},
            New WaterMeter With {.WaterMeterId = 5, .MeterNumber = "379-386-979", .Make = "Planetra", .Model = "P-2020", .MeterSize = "4 Inches"},
            New WaterMeter With {.WaterMeterId = 6, .MeterNumber = "580-742-825", .Make = "Kensa Sons", .Model = "KS2000A", .MeterSize = "1 3/4 Inches"},
            New WaterMeter With {.WaterMeterId = 7, .MeterNumber = "849-351-444", .Make = "Raynes Energica", .Model = "a1088", .MeterSize = "2 Inches"},
            New WaterMeter With {.WaterMeterId = 8, .MeterNumber = "208-428-308", .Make = "Constance Technologies", .Model = "808D", .MeterSize = "3/4 Inches"},
            New WaterMeter With {.WaterMeterId = 9, .MeterNumber = "738-588-249", .Make = "Warrington", .Model = "W4242", .MeterSize = "5/8 Inches"},
            New WaterMeter With {.WaterMeterId = 10, .MeterNumber = "496-813-794", .Make = "Estellano", .Model = "NCF-226", .MeterSize = "3/4 Inches"},
            New WaterMeter With {.WaterMeterId = 11, .MeterNumber = "862-715-006", .Make = "Warrington", .Model = "W-4040", .MeterSize = "1/2 Inch"},
            New WaterMeter With {.WaterMeterId = 12, .MeterNumber = "649-358-184", .Make = "Raynes Energica", .Model = "b1700", .MeterSize = "1 1/2 Inches"},
            New WaterMeter With {.WaterMeterId = 13, .MeterNumber = "928-317-924", .Make = "Gongola", .Model = "GN1000", .MeterSize = "2 Inch"},
            New WaterMeter With {.WaterMeterId = 14, .MeterNumber = "595-753-147", .Make = "Grass Grill", .Model = "CRC-1000", .MeterSize = "1 Inch"},
            New WaterMeter With {.WaterMeterId = 15, .MeterNumber = "799-528-461", .Make = "Kensa Sons", .Model = "K-584-L", .MeterSize = "3/4 Inches"},
            New WaterMeter With {.WaterMeterId = 16, .MeterNumber = "386-468-057", .Make = "Estellano", .Model = "NCF-226", .MeterSize = "3/4 Inches"},
            New WaterMeter With {.WaterMeterId = 17, .MeterNumber = "938-275-294", .Make = "Constance Technologies", .Model = "TT-8822", .MeterSize = "4 Inches"},
            New WaterMeter With {.WaterMeterId = 18, .MeterNumber = "288-427-585", .Make = "Planetra", .Model = "P-2020", .MeterSize = "1/2 Inch"},
            New WaterMeter With {.WaterMeterId = 19, .MeterNumber = "394-835-297", .Make = "Raynes Energica", .Model = "i2022", .MeterSize = "3/4 Inches"},
            New WaterMeter With {.WaterMeterId = 20, .MeterNumber = "847-252-246", .Make = "Master Stream", .Model = "2000-MS", .MeterSize = "1 1/2 Inches"},
            New WaterMeter With {.WaterMeterId = 21, .MeterNumber = "349-725-848", .Make = "Planetra", .Model = "P-8000", .MeterSize = "4 Inches"},
            New WaterMeter With {.WaterMeterId = 22, .MeterNumber = "713-942-058", .Make = "Master Stream", .Model = "3366-MS", .MeterSize = "3/4 Inches"},
            New WaterMeter With {.WaterMeterId = 23, .MeterNumber = "747-581-379", .Make = "Warrington", .Model = "W4242", .MeterSize = "5/8 Inches"},
            New WaterMeter With {.WaterMeterId = 24, .MeterNumber = "582-755-263", .Make = "Kensa Sons", .Model = "KS2000A", .MeterSize = "1 Inch"},
            New WaterMeter With {.WaterMeterId = 25, .MeterNumber = "827-260-758", .Make = "Raynes Energica", .Model = "a1088", .MeterSize = "1-1/4 Inch"},
            New WaterMeter With {.WaterMeterId = 26, .MeterNumber = "837-806-836", .Make = "Lansome", .Model = "7400", .MeterSize = "5/8 Inches"},
            New WaterMeter With {.WaterMeterId = 27, .MeterNumber = "207-964-835", .Make = "Constance Technologies", .Model = "TG-6220", .MeterSize = "5/8 Inches"},
            New WaterMeter With {.WaterMeterId = 28, .MeterNumber = "296-837-495", .Make = "Raynes Energica", .Model = "QG505", .MeterSize = "4 Inches"},
            New WaterMeter With {.WaterMeterId = 29, .MeterNumber = "468-359-486", .Make = "Grass Grill", .Model = "KLP-8822", .MeterSize = "1-1/4 Inch"},
            New WaterMeter With {.WaterMeterId = 30, .MeterNumber = "931-486-003", .Make = "Planetra", .Model = "P-2020", .MeterSize = "1/2 Inch"},
            New WaterMeter With {.WaterMeterId = 31, .MeterNumber = "483-770-648", .Make = "Warren", .Model = "WWW", .MeterSize = "0.1 Inches"},
            New WaterMeter With {.WaterMeterId = 32, .MeterNumber = "592-824-957", .Make = "Kensa Sons", .Model = "D-497-H", .MeterSize = "3/4 Inches"},
            New WaterMeter With {.WaterMeterId = 33, .MeterNumber = "293-835-704", .Make = "Gongola", .Model = "GOL1000", .MeterSize = "1/2 Inch"},
            New WaterMeter With {.WaterMeterId = 34, .MeterNumber = "739-777-749", .Make = "Warrington", .Model = "W2200W", .MeterSize = "3/4 Inches"},
            New WaterMeter With {.WaterMeterId = 35, .MeterNumber = "374-886-284", .Make = "Raynes Energica", .Model = "i2022", .MeterSize = "3/4 Inches"},
            New WaterMeter With {.WaterMeterId = 36, .MeterNumber = "186-959-757", .Make = "Kensa Sons", .Model = "M-686-G", .MeterSize = "1 1/2 Inches"},
            New WaterMeter With {.WaterMeterId = 37, .MeterNumber = "594-827-359", .Make = "Planetra", .Model = "P-8000", .MeterSize = "1 Inch"},
            New WaterMeter With {.WaterMeterId = 38, .MeterNumber = "394-739-242", .Make = "Master Stream", .Model = "9393-TT", .MeterSize = "5/8 Inches"},
            New WaterMeter With {.WaterMeterId = 39, .MeterNumber = "529-283-752", .Make = "Constance Technologies", .Model = "404T", .MeterSize = "3/4 Inches"},
            New WaterMeter With {.WaterMeterId = 40, .MeterNumber = "295-770-695", .Make = "Warrington", .Model = "W-2286", .MeterSize = "1-1/4 Inch"},
            New WaterMeter With {.WaterMeterId = 41, .MeterNumber = "739-749-737", .Make = "Kensa Sons", .Model = "KS2000A", .MeterSize = "1 Inch"},
            New WaterMeter With {.WaterMeterId = 42, .MeterNumber = "947-528-317", .Make = "Gondola", .Model = "GDL-5000", .MeterSize = "1 Inch"},
            New WaterMeter With {.WaterMeterId = 43, .MeterNumber = "630-207-055", .Make = "Lansome", .Model = "2800", .MeterSize = "3/4 Inches"},
            New WaterMeter With {.WaterMeterId = 44, .MeterNumber = "827-508-248", .Make = "Standard Trend", .Model = "428T", .MeterSize = "3/4 Inches"},
            New WaterMeter With {.WaterMeterId = 45, .MeterNumber = "293-924-869", .Make = "Grass Grill", .Model = "CRC-2020", .MeterSize = "1/2 Inch"},
            New WaterMeter With {.WaterMeterId = 46, .MeterNumber = "928-247-580", .Make = "Gondola", .Model = "GOL2000", .MeterSize = "0.34 Inch"},
            New WaterMeter With {.WaterMeterId = 47, .MeterNumber = "682-537-380", .Make = "Planetra", .Model = "P-2020", .MeterSize = "1-1/4 Inch"},
            New WaterMeter With {.WaterMeterId = 48, .MeterNumber = "470-628-850", .Make = "Estellano", .Model = "WRT-482", .MeterSize = "3/4 Inches"},
            New WaterMeter With {.WaterMeterId = 49, .MeterNumber = "649-373-505", .Make = "Constance Technologies", .Model = "BD-7000", .MeterSize = "5/8 Inches"},
            New WaterMeter With {.WaterMeterId = 50, .MeterNumber = "306-842-497", .Make = "Lansome", .Model = "9000", .MeterSize = "3/4 Inches"}
        }

        Dim strWaterMeters = Nothing
        Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

        Dim options = New JsonSerializerOptions()
        options.WriteIndented = True

        Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)
        Dim jsWaterMeters As String = JsonSerializer.Serialize(WaterMeters, GetType(List(Of WaterMeter)), options)
        File.WriteAllText(FiWaterMeters.FullName, jsWaterMeters)
    End Sub

    Private Sub CreateAccountsTypes()
        Dim Types = New List(Of AccountType)

        Types.Add(New AccountType With {.AccountTypeId = 1, .TypeCode = "OTH", .TypeDecription = "Other"})
        Types.Add(New AccountType With {.AccountTypeId = 3, .TypeCode = "RES", .TypeDecription = "Residential Household"})
        Types.Add(New AccountType With {.AccountTypeId = 2, .TypeCode = "BUS", .TypeDecription = "General Business, Commercial, Industrial"})
        Types.Add(New AccountType With {.AccountTypeId = 5, .TypeCode = "UUO", .TypeDecription = "Unidentified or Unclassified Type of Organization"})
        Types.Add(New AccountType With {.AccountTypeId = 4, .TypeCode = "SGO", .TypeDecription = "Social/Government/Non-Profit Organization, Institutional"})
        Types.Add(New AccountType With {.AccountTypeId = 6, .TypeCode = "WAT", .TypeDecription = "Water Intensive Business (Agricultural, Laudromat, Hair Salon, Restaurant, etc"})


        Dim StrAccountsTypes = Nothing
        Dim FileAccountsTypes = "C:\Stellar Water Point16\AccountsTypes.json"

        Dim Options = New JsonSerializerOptions()
        Options.WriteIndented = True

        Dim FiAccountsTypes As FileInfo = New FileInfo(FileAccountsTypes)
        Dim jsAccountsTypes = JsonSerializer.Serialize(Types, GetType(List(Of AccountType)), Options)
        File.WriteAllText(FiAccountsTypes.FullName, jsAccountsTypes)
    End Sub
    
    private sub WaterDistribution_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        REM        Directory.CreateDirectory("C:\Stellar Water Point16")

        CreateWaterMeters()
        CreateAccountsTypes()
    End Sub

    private sub BtnWaterMeters_Click(sender As Object, e As EventArgs) Handles BtnWaterMeters.Click
        Dim Listing = New WaterMetersCentral()

        Listing.Show()
    End Sub
End Class
  8. To execute the application, on the main menu, click Debug -> Start Without Debugging
  9. Close the forms and return to your programming environment
  10. Change the WaterDistribution.vb document as follows: 
    private sub WaterDistribution_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    REM Directory.CreateDirectory("C:\Stellar Water Point16")

    REM CreateWaterMeters()
    REM CreateAccountsTypes()
End Sub

Practical LearningPractical Learning: Introducing Customers

  1. To create a class, in the Solution Explorer, right-click Models -> Add -> Class...
  2. On the main menu, click Project -> Add Class...
  3. Replace the name with Customer
  4. Click Add
  5. Change the code as follows: 
    Public Class Customer
    Public Property CustomerId As Integer
    Public Property AccountNumber As String
    Public Property AccountName As String
    Public Property AccountType As String
    Public Property MeterNumber As String
    Public Property Address As String
    Public Property City As String
    Public Property County As String
    Public Property State As String
    Public Property ZIPCode As String
End Class

Displaying Customers

In a later section, we will learn how to create a customer record. When those records exist, a user can display them. We are going to make it possible through a form equipped with a list view

Practical LearningPractical Learning: Displaying Customers

  1. To create a form, in the Solution Explorer, right-click StellarWaterPoint2 -> Add -> Form (Windows Forms)...
  2. For the Name of the form, type CustomersCentral
  3. Click Add
  4. In the Toolbox, click the ListView button and click the form
  5. On the form, right-click the list view and click Edit Columns...
  6. Create the columns as follows:
    (Name) Text TextAlign Width
    ColCustomerId Id   40
    ColAccountNumber Account # Center 150
    ColAccountName Account Name   200
    ColAccountType Account Type   200
    ColMeterNumber Meter # Center 100
    ColAddress Address   250
    ColCity City   125
    ColCounty County   125
    ColState State Center  
    ColZIPCode ZIP-Code Center 125
  7. Click OK
  8. Position and resize the list view on the form as follows:

    Stellar Water Point - Customers

    Control (Name) Other Properties
    ListView List View LvwCustomers FullRowSelect: True
    GridLines: True
    View: Details
  9. Right-click any area of the form and click View Code
  10. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class CustomersCentral

    Private Sub ShowCustomers()
        Dim StrCustomers = Nothing
        Dim Customers As List(Of Customer) = New List(Of Customer)
        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)
        Dim StrAccountsTypes = Nothing
        Dim AccountsTypes = New List(Of AccountType)
        Dim FileAccountsTypes = "C:\Stellar Water Point16\AccountsTypes.json"

        Dim FiAccountsTypes As FileInfo = New FileInfo(FileAccountsTypes)

        If FiCustomers.Exists = True Then
            Using TrCustomers As TextReader = New StreamReader(FiCustomers.FullName)
                StrCustomers = File.ReadAllText(FiCustomers.FullName)
                Customers = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))

                LvwCustomers.Items.Clear()

                For Each Client As Customer In Customers
                    Dim LviCustomer As ListViewItem = New ListViewItem(CStr(Client.CustomerId))

                    LviCustomer.SubItems.Add(Client.AccountNumber)
                    LviCustomer.SubItems.Add(Client.AccountName)
                    LviCustomer.SubItems.Add(Client.MeterNumber)

                    Dim TrAccountsTypess As TextReader = New StreamReader(FiAccountsTypes.FullName)
                    StrAccountsTypes = File.ReadAllText(FiAccountsTypes.FullName)
                    AccountsTypes = JsonSerializer.Deserialize(StrAccountsTypes, GetType(List(Of AccountType)))

                    For Each ActType As AccountType In AccountsTypes
                        If Client.AccountType = ActType.TypeCode Then
                            LviCustomer.SubItems.Add(String.Concat(ActType.TypeCode, " - ", ActType.TypeDecription))
                        End If
                    Next

                    LviCustomer.SubItems.Add(Client.Address)
                    LviCustomer.SubItems.Add(Client.City)
                    LviCustomer.SubItems.Add(Client.County)
                    LviCustomer.SubItems.Add(Client.State)
                    LviCustomer.SubItems.Add(Client.ZIPCode)
                    LvwCustomers.Items.Add(LviCustomer)
                Next
            End Using
        End If
    End Sub

    Private Sub CustomersCentral_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ShowCustomers()
    End Sub
End Class
  11. In the Solution Explorer, double-click WaterDistribution.vb to display the main form of the application
  12. From the Toolbox, add a button to the form
  13. From the Properties window, change the characteristics of the button as follows:

    Stellar Water Point

    Control (Name) Text Font
    Button Button BtnCustomers C&ustomers... Times New Roman, 24pt, style=Bold
  14. Right-click andy part of the form and click View Code
  15. Impliment the Click event of the Customers as follows: 
    Private Sub BtnCustomers_Click(sender As Object, e As EventArgs) Handles BtnCustomers.Click
    Dim Central = New CustomersCentral

    Central.ShowDialog()
End Sub

A New Customer Account

To use the services of a water distribution company, a customer must have an account. We are going to create a form that an employee can use to establish an account for a new customer.

Practical LearningPractical Learning: Creating a Customer Account

  1. To create a form, in the Solution Explorer, right-click StellarWaterPoint2 -> Add -> Form (Windows Forms)...
  2. For the Name of the file, type CustomersCreate as the name of the form
  3. Click Add
  4. Design the form as follows:

    Stellar Water Point - New Customer Account

    Control (Name) Text Other Properties
    Label Label   &Account #:  
    MaskedTextBox Masked Text Box MtbAccountNumber   Masked: 0000-000-0000
    Label Label   &Account Name:  
    TextBox Text Box TxtAccountName    
    Label Label   &Meter #:  
    MaskedTextBox Masked Text Box MtbMeterNumber   Masked: 000-000-000
    Button Button BtnFindWaterMeter &Find Water Meter  
    Label Label   Meter &Details:  
    TextBox Text Box TxtMeterDetails   Enabled: False
    Label Label   &Account Type:  
    ComboBox Combo Box cbxAccountsTypes  
    Label Label   &Address:  
    TextBox Text Box TxtAddress    
    Label Label   C&ity:  
    TextBox Text Box TxtCity    
    Label Label   C&ounty:  
    TextBox Text Box TxtCounty    
    Label Label   &State:  
    TextBox Text Box TxtState    
    Label Label   &ZIP-Code:  
    MaskedTextBox Masked Text Box MtbZIPCode   Masked: Zip-Code
    Label Label   Customer Id:&  
    TextBox Text Box TxtCustomerId    
    Button Button BtnSaveCustomerAccount S&ave Customer Account DialogResult: OK
    Button Button BtnClose &Close DialogResult: Cancel
  5. Using the Properties window, change some characteristics of the form as follows: 
    FormBorderStyle: FixedDialog
Text:            Stellar Water Point - Create Customer Account
StartPosition:   CenterScreen
AcceptButton:    BtnSaveCustomerAccount
CancelButton:    BtnCancel
  6. Right-click an area of the form and click View Code
  7. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class CustomersCreate
    Private Sub SetCustomerId()
        Dim StrCustomers = Nothing
        Dim Customers As List(Of Customer) = New List(Of Customer)
        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)

        Dim CustomerId = 0

        If FiCustomers.Exists = True Then
            Using TrCustomers As TextReader = New StreamReader(FiCustomers.FullName)
                StrCustomers = File.ReadAllText(FiCustomers.FullName)
                Customers = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))

                For Each Client As Customer In Customers
                    CustomerId = Client.CustomerId
                Next
            End Using
        End If

        TxtCustomerId.Text = CStr(CustomerId + 1)
    End Sub

    Private Sub SetAccountsTypes()
        Dim StrAccountsTypes = Nothing
        Dim Types As List(Of AccountType) = New List(Of AccountType)
        Dim FileAccountsTypes = "C:\Stellar Water Point16\AccountsTypes.json"
        Dim FiAccountsTypes As FileInfo = New FileInfo(FileAccountsTypes)

        If FiAccountsTypes.Exists = True Then
            StrAccountsTypes = File.ReadAllText(FiAccountsTypes.FullName)
            Types = JsonSerializer.Deserialize(StrAccountsTypes, GetType(List(Of AccountType)))

            For Each Type As AccountType In Types
                CbxAccountsTypes.Items.Add(Type.TypeCode & " - " & Type.TypeDecription)
            Next
        End If
    End Sub

    Private Sub CustomersCreate_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        SetCustomerId()
        SetAccountsTypes()
    End Sub

    Private Sub BtnFindWaterMeter_Click(sender As Object, e As EventArgs) Handles BtnFindWaterMeter.Click
        If MtbMeterNumber.Text.Replace("-", "").Trim().Equals(Nothing) Then
            MsgBox("You must type a valid meter number, " &
                   "and then click the Find Water Meter button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim strWaterMeters = Nothing
        Dim WaterMeters As List(Of WaterMeter) = New List(Of WaterMeter)
        Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

        Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

        If FiWaterMeters.Exists = True Then
            strWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
            WaterMeters = JsonSerializer.Deserialize(strWaterMeters, GetType(List(Of WaterMeter)))

            For Each Meter As WaterMeter In WaterMeters
                If Meter.MeterNumber = MtbMeterNumber.Text Then
                    TxtMeterDetails.Text = Meter.WaterMeterId.ToString() & " - " &
                                       Meter.Make & " " &
                                       Meter.Model &
                                       " (Meter Size: " & Meter.MeterSize & ")"
                End If
            Next
        End If
    End Sub
End Class
  8. In the Solution Explorer, below the Customers folder, double-click CustomersCentral.vb
  9. From the Toolbox, add a button to the form below the list view
  10. Change the characteristics of the button as follows:

    Stellar Water Point - Water Meters

    Control (Name) Other Properties
    ListView List View LvwCustomers FullRowSelect: True
    GridLines: True
    View: Details
    Button Button BtnNewCustomerAccount &New Customer Account...
  11. Right-click the body of the form and click View Code
  12. Create an event as follows: 
    Private Sub BtnCreateCustomerAccount_Click(sender As Object, e As EventArgs) Handles BtnCreateCustomerAccount.Click
    Dim Create As CustomersCreate = New CustomersCreate()

    If Create.ShowDialog() = DialogResult.OK Then
        If Create.MtbAccountNumber.Text.Replace("-", "").Trim().Equals("") Then
            MsgBox("You must provide an account number for a new customer. " &
                   "Otherwise, the account cannot be created.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        If Create.MtbMeterNumber.Text.Replace("-", "").Trim().Equals(Nothing) Then
            MsgBox("You must type a valid meter number to associate " &
                   "a water meter to a customer's account. After providing " &
                   "a meter number, click the Find Water Meter button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrCustomers = Nothing
        Dim Clients As List(Of Customer) = New List(Of Customer)
        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)

        If FiCustomers.Exists = True Then
            StrCustomers = File.ReadAllText(FiCustomers.FullName)
            Clients = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))
        End If

        Dim Consumer As Customer = New Customer With {
            .CustomerId = CInt(Create.TxtCustomerId.Text),
            .AccountNumber = Create.MtbAccountNumber.Text,
            .AccountName = Create.TxtAccountName.Text,
            .AccountType = Create.CbxAccountsTypes.Text.Substring(0, 3),
            .MeterNumber = Create.MtbMeterNumber.Text,
            .Address = Create.TxtAddress.Text,
            .City = Create.TxtCity.Text,
            .County = Create.TxtCounty.Text,
            .State = Create.TxtState.Text,
            .ZIPCode = Create.MtbZIPCode.Text
        }

        Clients.Add(Consumer)

        Dim options = New JsonSerializerOptions()
        options.WriteIndented = True

        Dim jsCustomers As String = JsonSerializer.Serialize(Clients, GetType(List(Of Customer)), options)
        File.WriteAllText(FiCustomers.FullName, jsCustomers)
    End If

    ShowCustomers()
End Sub
  13. To execute the application, on the main menu, click Debug -> Start Without Debugging:

    Stellar Water Point - New Customer Account

  14. On the Water Distribution form, click the Customers button:

    Stellar Water Point - Customers Accounts

  15. On the Central form of the customers, click the Create Customer Account button:

    Stellar Water Point - Customers Accounts

  16. In the account # text box, type 9279-570-8394
  17. In the meter # text box, type 799-528-461
  18. Click the Find water meter button
  19. Enter the other values as follows: 
    Account #:    9279-570-8394
Account Name: Thomas Stones
Meter #:      799-528-461
Account Type: RES - Residential Household
Address:      10252 Broward Ave #D4
City:         Frederick
County:       Frederick
State:        MD
ZIP-Code:     21703-4422

    Stellar Water Point - New Customer Account

  20. Click Save Customer Account
  21. In the same way, create the following two records:

    Account # Account Name Meter # Account Type Address City County State ZIP-Code
    4086-938-4783 Hernola Dough 594-827-359 UUO - Unidentified or Unclassified Type of Organization 10 10 Hexagonal Drv Winston Yoke Penn 11402-4411
    7080-583-5947 Sunny Yard 827-508-248 WAT - Water Intensive Business(Laudromat, Hair Salon, Restaurant, etc 663 Sherry Wood East Street Shimpstown Franklin PA 17236-2626

    Stellar Water Point - Customers

  22. Close the forms and return to your programming environment

Customer Account Details

When a customer account has been created, at any time, an employee may want to simply review such an account. Our application needs a form for that.

Practical LearningPractical Learning: Showing Customer Account

  1. To create a form, in the Solution Explorer, right-click StellarWaterPoint2 -> Add -> Form (Windows Forms)...
  2. For the Name of the form, type CustomersDetails
  3. Press Enter
  4. Design the form as follows:

    Stellar Water Point - New Customer Account

    Control (Name) Text Other Properties
    Label Label   &Account #:  
    MaskedTextBox Masked Text Box MtbAccountNumber   Masked: 0000-000-0000
    Button Button BtnFindCustomerAccount &Find Customer Account  
    Label Label   &Account Name:  
    TextBox Text Box TxtAccountName   Enabled: False
    Label Label   Meter &Details:  
    TextBox Text Box TxtMeterDetails   Enabled: False
    Label Label   &Account Type:  
    TextBox Combo Box TxtAccountsTypes   Enabled: False
    Label Label   &Address:  
    TextBox Text Box TxtAddress   Enabled: False
    Label Label   C&ity:  
    TextBox Text Box TxtCity   Enabled: False
    Label Label   C&ounty:  
    TextBox Text Box TxtCounty   Enabled: False
    Label Label   &State:  
    TextBox Text Box TxtState   Enabled: False
    Label Label   &ZIP-Code:  
    TextBox Masked Text Box TxtZIPCode   Enabled: False
    Label Label   Customer Id:&:  
    TextBox Text Box TxtCustomerId   Enabled: False
    Button Button BtnClose &Close  
  5. Right-click any area of the form and click View Code
  6. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class CustomersDetails
    Private Sub btnFindCustomerAccount_Click(sender As Object, e As EventArgs) Handles BtnFindCustomerAccount.Click
        If MtbAccountNumber.Text.Replace("-", "").Trim() = "" Then
            MsgBox("You must type a valid account number of a customer, " &
                            "and then click the Find Customer Account button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrCustomers = String.Empty
        Dim StrAccountType = String.Empty
        Dim Clients As List(Of Customer) = New List(Of Customer)
        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)

        Dim StrMeterNumber = Nothing

        If FiCustomers.Exists = True Then
            Using TrCustomers As TextReader = New StreamReader(FiCustomers.FullName)
                StrCustomers = File.ReadAllText(FiCustomers.FullName)
                Clients = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))

                Dim Customers As IEnumerable(Of Customer) = From consumer
                                                            In Clients
                                                            Where consumer.AccountNumber = MtbAccountNumber.Text
                                                            Select consumer

                For Each Client As Customer In Customers
                    TxtCustomerId.Text = Client.CustomerId
                    TxtAccountName.Text = Client.AccountName
                    StrMeterNumber = Client.MeterNumber
                    StrAccountType = Client.AccountType
                    TxtAddress.Text = Client.Address
                    TxtCity.Text = Client.City
                    TxtCounty.Text = Client.County
                    TxtState.Text = Client.State
                    TxtZIPCode.Text = Client.ZIPCode
                Next
            End Using
        End If

        If Len(StrMeterNumber) > 0 Then
            Dim StrWaterMeters = Nothing
            Dim WaterMeters As List(Of WaterMeter) = New List(Of WaterMeter)
            Dim fileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

            Dim fiWaterMeters As FileInfo = New FileInfo(fileWaterMeters)

            If fiWaterMeters.Exists = True Then
                StrWaterMeters = File.ReadAllText(fiWaterMeters.FullName)
                WaterMeters = JsonSerializer.Deserialize(StrWaterMeters, GetType(List(Of WaterMeter)))

                Dim Meters As IEnumerable(Of WaterMeter) = From measure
                                                                     In WaterMeters
                                                           Where measure.MeterNumber = StrMeterNumber
                                                           Select measure

                For Each Meter As WaterMeter In WaterMeters
                    TxtMeterDetails.Text = Meter.Make & " " &
                                           Meter.Model &
                                           " (Meter Size: " & Meter.MeterSize & ")"
                Next
            End If
        End If

        Dim StrAccountsTypes = Nothing
        Dim Types As List(Of AccountType) = New List(Of AccountType)
        Dim fileAccountsTypes = "C:\Stellar Water Point16\AccountsTypes.json"

        Dim FiAccountsTypes As FileInfo = New FileInfo(fileAccountsTypes)

        If FiAccountsTypes.Exists = True Then
            StrAccountsTypes = File.ReadAllText(FiAccountsTypes.FullName)
            Types = JsonSerializer.Deserialize(StrAccountsTypes, GetType(List(Of AccountType)))

            Dim ActType As IEnumerable(Of AccountType) = From category
                                                         In Types
                                                         Where category.TypeCode = StrAccountType
                                                         Select category


            For Each Type As AccountType In Types
                TxtAccountType.Text = $"{Type.TypeCode } - {Type.TypeDecription}"
            Next
        End If
    End Sub

    Private Sub btnClose_Click(sender As Object, e As EventArgs) Handles BtnClose.Click
        Close()
    End Sub
End Class
  7. In the Solution Explorer, double-click CustomersCentral.vb to open its form
  8. From the Toolbox, add a button to the form below the list view and to the right of the New Customer Account button
  9. Change the characteristics of the button as follows:

    Stellar Water Point - Customer Account Details

    Control (Name) Other Properties
    ListView List View LvwCustomers No Change
    Button Button No Change No Change
    Button Button BtnCustomerAccountDetails Customer Account &Details...
  10. Double-click the Customer Account &Details button
  11. Change the document as follows: 
    Private Sub BtnCustomerAccountDetails_Click(sender As Object, e As EventArgs) Handles BtnCustomerAccountDetails.Click
    Dim Details As CustomersDetails = New CustomersDetails()

    Details.Show()
End Sub
  12. To execute the application, on the main menu, click Debug -> Start Without Debugging

    Stellar Water Point

  13. On the Water Distribution form, click the Customers button
  14. On the Central form of the customers form, click the Customer Account &Details button:

    Stellar Water Point - View Water Meter

  15. In the Account # text, type 4086-938-4783
  16. Click the Find Customer Account button:

    Stellar Water Point - View Water Meter

  17. Close the forms and return to your programming environment

Editing a Customer Account

When a piece of information has changed about a customer, an employee should update the customer account. We will provide a for such an operation.

Practical LearningPractical Learning: Editing a Customer Account

  1. To create a form, in the Solution Explorer, right-click StellarWaterPoint2 -> Add -> Form (Windows Forms)...
  2. For the Name of the file, type CustomersEditor as the name of the form
  3. Click Add
  4. Design the form as follows:

    Stellar Water Point - Customer Account Editor

    Control (Name) Text Other Properties
    Label Label   &Account #:  
    MaskedTextBox Masked Text Box MtbAccountNumber   Masked: 0000-000-0000
    Button Button BtnFindCustomerAccount &Find Customer Account  
    Label Label   &Account Name:  
    TextBox Text Box TxtAccountName    
    Label Label   &Meter #:  
    MaskedTextBox Masked Text Box MtbMeterNumber   Masked: 000-000-000
    Button Button BtnFindWaterMeter Find &Water Meter  
    Label Label   Meter &Details:  
    TextBox Text Box TxtMeterDetails   Enabled: False
    Label Label   &Account Type:  
    ComboBox Combo Box cbxAccountsTypes  
    Label Label   &Address:  
    TextBox Text Box TxtAddress    
    Label Label   C&ity:  
    TextBox Text Box TxtCity    
    Label Label   C&ounty:  
    TextBox Text Box TxtCounty    
    Label Label   &State:  
    TextBox Text Box TxtState    
    Label Label   &ZIP-Code:  
    MaskedTextBox Masked Text Box MtbZIPCode   Masked: Zip-Code
    Label Label   Customer Id:&:  
    TextBox Text Box TxtCustomerId   Enabled: False
    Button Button BtnUpdateCustomerAccount &Update Customer Account DialogResult: OK
    Button Button BtnClose &Close DialogResult: Cancel
  5. Right-click any area of the form cnad click View Code
  6. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class CustomersEditor
    Private Sub Editor_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim StrAccountsTypes = Nothing
        Dim Types As List(Of AccountType) = New List(Of AccountType)
        Dim FileAccountsTypes = "C:\Stellar Water Point16\AccountsTypes.json"

        Dim FiAccountsTypes As FileInfo = New FileInfo(FileAccountsTypes)

        If FiAccountsTypes.Exists = True Then
            StrAccountsTypes = File.ReadAllText(FiAccountsTypes.FullName)
            Types = JsonSerializer.Deserialize(StrAccountsTypes, GetType(List(Of AccountType)))

            For Each ActType As AccountType In Types
                CbxAccountsTypes.Items.Add(ActType.TypeCode & " - " & ActType.TypeDecription)
            Next
        End If
    End Sub

    Private Sub BtnFindCustomerAccount_Click(sender As Object, e As EventArgs) Handles BtnFindCustomerAccount.Click
        If MtbAccountNumber.Text.Replace("-", "").Trim() = "" Then
            MsgBox("You must type a valid account number of a customer, " &
                   "and then click the Find Customer Account button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrCustomers = Nothing
        Dim StrAccountType = Nothing
        Dim Clients As List(Of Customer) = New List(Of Customer)
        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)

        If FiCustomers.Exists = True Then
            Using TrCustomers As TextReader = New StreamReader(FiCustomers.FullName)
                StrCustomers = File.ReadAllText(FiCustomers.FullName)
                Clients = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))

                Dim Customers As IEnumerable(Of Customer) = From consumer
                                                            In Clients
                                                            Where consumer.AccountNumber = MtbAccountNumber.Text
                                                            Select consumer

                For Each Client As Customer In Customers
                    TxtCustomerId.Text = Client.CustomerId.ToString()
                    TxtAccountName.Text = Client.AccountName
                    MtbMeterNumber.Text = Client.MeterNumber
                    StrAccountType = Client.AccountType
                    TxtAddress.Text = Client.Address
                    TxtCity.Text = Client.City
                    TxtCounty.Text = Client.County
                    TxtState.Text = Client.State
                    MtbZIPCode.Text = Client.ZIPCode
                Next
            End Using
        End If

        If Len(MtbAccountNumber.Text) > 0 Then
            Dim strWaterMeters = Nothing
            Dim WaterMeters As List(Of WaterMeter) = New List(Of WaterMeter)
            Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

            Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

            If FiWaterMeters.Exists = True Then
                strWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
                WaterMeters = JsonSerializer.Deserialize(strWaterMeters, GetType(List(Of WaterMeter)))

                Dim Meters As IEnumerable(Of WaterMeter) = From measure
                                                           In WaterMeters
                                                           Where measure.MeterNumber = MtbMeterNumber.Text
                                                           Select measure

                For Each Meter As WaterMeter In WaterMeters
                    TxtMeterDetails.Text = Meter.Make & " " &
                                           Meter.Model &
                                           " (Meter Size: " & Meter.MeterSize & ")"
                Next
            End If
        End If

        Dim StrAccountsTypes = Nothing
        Dim Types As List(Of AccountType) = New List(Of AccountType)
        Dim FileAccountsTypes = "C:\Stellar Water Point16\AccountsTypes.json"

        Dim FiAccountsTypes As FileInfo = New FileInfo(FileAccountsTypes)

        If FiAccountsTypes.Exists = True Then
            StrAccountsTypes = File.ReadAllText(FiAccountsTypes.FullName)
            Types = JsonSerializer.Deserialize(StrAccountsTypes, GetType(List(Of AccountType)))

            Dim ActType As IEnumerable(Of AccountType) = From category
                                                         In Types
                                                         Where category.TypeCode = StrAccountType
                                                         Select category


            For Each Type As AccountType In Types
                CbxAccountsTypes.Text = $"{Type.TypeCode} - {Type.TypeDecription}"
            Next
        End If
    End Sub

    Private Sub BtnFindWaterMeter_Click(sender As Object, e As EventArgs) Handles BtnFindWaterMeter.Click
        If MtbMeterNumber.Text.Replace("-", "").Trim().Equals(Nothing) Then
            MsgBox("You must type a valid meter number, " &
                   "and then click the Find Water Meter button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrWaterMeters = Nothing
        Dim WaterMeters As List(Of WaterMeter) = New List(Of WaterMeter)
        Dim FileWaterMeters = "C:\Stellar Water Point2\WaterMeters.json"

        Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

        If FiWaterMeters.Exists = True Then
            StrWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
            WaterMeters = JsonSerializer.Deserialize(StrWaterMeters, GetType(List(Of WaterMeter)))

            For Each Meter As WaterMeter In WaterMeters
                If Meter.MeterNumber = MtbMeterNumber.Text Then
                    TxtMeterDetails.Text = Meter.Make & " " &
                                           Meter.Model &
                                           " (Meter Size: " & Meter.MeterSize & ")"
                End If
            Next
        End If
    End Sub

    Private Sub BtnUpdateCustomerAccount_Click(sender As Object, e As EventArgs) Handles BtnUpdateCustomerAccount.Click
        If String.IsNullOrEmpty(MtbAccountNumber.Text) Then
            MsgBox("Please enter an account number for a customer. " &
                   "You can then click the Find Customer Account button " &
                   "to indicate the customer whose account you want o update.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        If String.IsNullOrEmpty(MtbMeterNumber.Text) Then
            MsgBox("You must type a valid meter number, " &
                   "and then click the Find Water Meter button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrCustomers As String = Nothing
        Dim Clients As List(Of Customer) = New List(Of Customer)
        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"

        Dim FiCustomers As FileInfo = New FileInfo(fileCustomers)

        If fiCustomers.Exists = True Then
            StrCustomers = File.ReadAllText(FiCustomers.FullName)
            Clients = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))

            Dim Client As Customer = Clients.Find(Function(Cust) Cust.AccountNumber = MtbAccountNumber.Text)

            If Not Client Is Nothing Then
                Client.CustomerId = TxtCustomerId.Text
                Client.AccountNumber = MtbAccountNumber.Text
                Client.AccountName = TxtAccountName.Text
                Client.MeterNumber = MtbMeterNumber.Text
                Client.AccountType = CbxAccountsTypes.Text.Substring(0, 3)
                Client.Address = TxtAddress.Text
                Client.City = TxtCity.Text
                Client.County = TxtCounty.Text
                Client.State = TxtState.Text
                Client.ZIPCode = MtbZIPCode.Text

                Dim Options As JsonSerializerOptions = New JsonSerializerOptions()
                Options.WriteIndented = True

                Dim JsCustomers As String = JsonSerializer.Serialize(Clients, GetType(List(Of Customer)), Options)
                File.WriteAllText(FiCustomers.FullName, JsCustomers)
            End If
        End If

        Close()
    End Sub

    Private sub BtnClose_Click(sender As Object, e As EventArgs) handles btnclose.click
            Close()
        end sub
End Class
  7. In the Solution Explorer, below the Customers folder, double-click Central.vb
  8. From the Toolbox, add a button to the form below the list view and on the right side of the Customer Account Editor button
  9. Change the characteristics of the button as follows:

    Stellar Water Point - Water Meters

    Control (Name) Other Properties
    ListView List View LvwCustomers No Change
    Button Button BtnNewCustomerAccount No Change
    Button Button BtnCustomerAccountDetails No Change
    Button Button BtnUpdateCustomerAccount &Update Customer Account...
  10. Display the Central form of the Customers folder
  11. Double-click the Update Customer Account button
  12. Change the document as follows: 
    Private Sub BtnCustomerAccountEditor_Click(sender As Object, e As EventArgs) Handles BtnCustomerAccountEditor.Click
    Dim Editor As CustomersEditor = New CustomersEditor()

    Editor.ShowDialog()

    ShowCustomers()
End Sub
  13. To execute the application, on the main menu, click Debug -> Start Without Debugging

    Stellar Water Point

  14. On the main form of the application, click the Customers button:

    Stellar Water Point - Customers

  15. Click the Edit Customer Account button:

    Stellar Water Point - Customer Account Editor

  16. In the Account # text, type 4086-938-4783
  17. Click the Find Customer Account button

    Stellar Water Point - Customer Account Editor

  18. Change the values as follows: 
    Account Name: Bernotte Doughnuts
Meter #:      580-742-825 and click Find Water Meter
Account Type: BUS - General Business, Commercial, Industrial
Address:      10103 Hexagon Drive
City:         Winterstown
County:       York
State:        PA
ZIP-Code:     17402-8828

    Stellar Water Point - Customer Account Editor

  19. Click the Update Customer Account button:

    Stellar Water Point - Customers Accounts

  20. Close the forms and return to your programming environment

Deleting a Customer Account from the Database

If an employee realizes that a customer account must not exist anymore, the employee can delete that account. We will provide a form for such an operation.

Practical LearningPractical Learning: Deleting a Customer Account

  1. To create a form, in the Solution Explorer, right-click Customers -> Add -> Form (Windows Forms)...
  2. In the Name text box, replace the string with Delete as the name of the form
  3. Press Enter
  4. Design the form as follows:

    Stellar Water Point - Customer Account Deletion

    Control (Name) Text Other Properties
    Label Label   &Account #:  
    MaskedTextBox Masked Text Box MtbAccountNumber   Masked: 0000-000-0000
    Button Button BtnFindCustomerAccount &Find Customer Account  
    Label Label   &Account Name:  
    TextBox Text Box TxtAccountName   Enabled: False
    Label Label   Meter &Details:  
    TextBox Text Box TxtMeterDetails   Enabled: False
    Label Label   &Account Type:  
    TextBox Combo Box TxtAccountsTypes   Enabled: False
    Label Label   &Address:  
    TextBox Text Box TxtAddress   Enabled: False
    Label Label   C&ity:  
    TextBox Text Box TxtCity   Enabled: False
    Label Label   C&ounty:  
    TextBox Text Box TxtCounty   Enabled: False
    Label Label   &State:  
    TextBox Text Box TxtState   Enabled: False
    Label Label   &ZIP-Code:  
    TextBox Masked Text Box TxtZIPCode   Enabled: False
    Button Button BtnDeleteCustomerAccount &Delete Customer Account  
    Button Button BtnClose &Close  
  5. Right-click any part of the form and click View Code
  6. Change the document as tollows: 
    Imports System.IO
Imports System.Text.Json

Public Class CustomersDelete
    Private Sub BtnFindCustomerAccount_Click(sender As Object, e As EventArgs) Handles BtnFindCustomerAccount.Click
        If MtbAccountNumber.Text.Replace("-", "").Trim() = "" Then
            MsgBox("You must type a valid account number of a customer, " &
                            "and then click the Find Customer Account button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrCustomers = Nothing
        Dim StrAccountType = Nothing
        Dim Clients As List(Of Customer) = New List(Of Customer)
        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)

        Dim strMeterNumber = Nothing

        If FiCustomers.Exists = True Then
            Using TrCustomers As TextReader = New StreamReader(FiCustomers.FullName)
                StrCustomers = File.ReadAllText(FiCustomers.FullName)
                Clients = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))

                Dim Customers As IEnumerable(Of Customer) = From consumer
                                                            In Clients
                                                            Where consumer.AccountNumber = MtbAccountNumber.Text
                                                            Select consumer

                For Each Client As Customer In Clients
                    TxtCustomerId.Text = Client.CustomerId
                    TxtAccountName.Text = Client.AccountName
                    strMeterNumber = Client.MeterNumber
                    StrAccountType = Client.AccountType
                    TxtAddress.Text = Client.Address
                    TxtCity.Text = Client.City
                    TxtCounty.Text = Client.County
                    TxtState.Text = Client.State
                    TxtZIPCode.Text = Client.ZIPCode
                Next
            End Using
        End If

        If Len(strMeterNumber) > 0 Then
            Dim strWaterMeters = Nothing
            Dim WaterMeters As List(Of WaterMeter) = New List(Of WaterMeter)
            Dim FileWaterMeters = "C:\Stellar Water Point2\WaterMeters.json"

            Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

            If FiWaterMeters.Exists = True Then
                strWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
                WaterMeters = JsonSerializer.Deserialize(strWaterMeters, GetType(List(Of WaterMeter)))

                Dim Meters As IEnumerable(Of WaterMeter) = From measure
                                                           In WaterMeters
                                                           Where measure.MeterNumber = strMeterNumber
                                                           Select measure

                For Each Meter As WaterMeter In WaterMeters
                    TxtMeterDetails.Text = Meter.Make & " " &
                                           Meter.Model &
                                           " (Meter Size: " & Meter.MeterSize & ")"
                Next
            End If
        End If

        Dim StrAccountsTypes = Nothing
        Dim Types As List(Of AccountType) = New List(Of AccountType)
        Dim FileAccountsTypes = "C:\Stellar Water Point16\AccountsTypes.json"

        Dim FiAccountsTypes As FileInfo = New FileInfo(FileAccountsTypes)

        If FiAccountsTypes.Exists = True Then
            StrAccountsTypes = File.ReadAllText(FiAccountsTypes.FullName)
            Types = JsonSerializer.Deserialize(StrAccountsTypes, GetType(List(Of AccountType)))

            Dim ActType As IEnumerable(Of AccountType) = From category
                                                         In Types
                                                         Where category.TypeCode = StrAccountType
                                                         Select category


            For Each Type As AccountType In Types
                TxtAccountType.Text = $"{Type.TypeCode} - {Type.TypeDecription}"
            Next
        End If
    End Sub

    Private Sub BtnDeleteCustomerAccount_Click(sender As Object, e As EventArgs) Handles BtnDeleteCustomerAccount.Click
        If MtbAccountNumber.Text.Replace("-", "").Trim() = "" Then
            MsgBox("You must type a valid account number of a customer, " &
                   "and then click the Find Customer Account button. " &
                   "Only then can you delete an customer account.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrCustomers = Nothing
        Dim Clients As List(Of Customer) = New List(Of Customer)
        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)

        If FiCustomers.Exists = True Then
            StrCustomers = File.ReadAllText(FiCustomers.FullName)
            Clients = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))

            Dim Client As Customer = Clients.Find(Function(Acnt) Acnt.AccountNumber = MtbAccountNumber.Text)

            If Not Client Is Nothing Then
                If MsgBox("Are you sure you want to delete this customer's account " &
                          "(you cannot undo the action)?",
                          MsgBoxStyle.YesNoCancel, "Stellar Water Point") = MsgBoxResult.Yes Then
                    Clients.Remove(Client)

                    Dim Options As JsonSerializerOptions = New JsonSerializerOptions()
                    Options.WriteIndented = True

                    Dim JsCustomers As String = JsonSerializer.Serialize(Clients, GetType(List(Of Customer)), Options)
                    File.WriteAllText(FiCustomers.FullName, JsCustomers)

                    MsgBox("The customer's account has been deleted from our system.",
                           MsgBoxStyle.OkOnly, "Stellar Water Point")
                End If
            End If
        End If

        Close()
    End Sub

    Private Sub BtnClose_Click(sender As Object, e As EventArgs) Handles BtnClose.Click
        Close()
    End Sub
End Class
  7. In the Solution Explorer, below the Customers folder, double-click Central.vb
  8. From the Toolbox, add two buttons to the form below the list view and on the right side of the Update Customer Account button
  9. Change the characteristics of the buttons as follows:

    Stellar Water Point - Water Meters

    Control (Name) Other Properties
    ListView List View LvwCustomers FullRowSelect: True
    GridLines: True
    View: Details
    Anchor: Top, Bottom, Left, Right
    Button Button BtnCreateCustomerAccount Create Customer &Account....
    Anchor: Bottom, Right
    Button Button BtnCustomerAccountDetails Customer Account &Details...
    Anchor: Bottom, Right
    Button Button BtnEditCustomerAccount &Edit Customer Account...
    Anchor: Bottom, Right
    Button Button BtnDeleteCustomerAccount &Delete Customer Account...
    Anchor: Bottom, Right
    Button Button BtnClose &Close
    Anchor: Bottom, Right
  10. Right-click andy area of the form and click View Code
  11. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class CustomersCentral
    Private Sub ShowCustomers()
        Dim StrCustomers = Nothing
        Dim Customers As List(Of Customer) = New List(Of Customer)
        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)
        Dim StrAccountsTypes = Nothing
        Dim AccountsTypes = New List(Of AccountType)
        Dim FileAccountsTypes = "C:\Stellar Water Point16\AccountsTypes.json"

        Dim FiAccountsTypes As FileInfo = New FileInfo(FileAccountsTypes)

        If FiCustomers.Exists = True Then
            Using TrCustomers As TextReader = New StreamReader(FiCustomers.FullName)
                StrCustomers = File.ReadAllText(FiCustomers.FullName)
                Customers = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))

                LvwCustomers.Items.Clear()

                For Each Client As Customer In Customers
                    Dim LviCustomer As ListViewItem = New ListViewItem(CStr(Client.CustomerId))

                    LviCustomer.SubItems.Add(Client.AccountNumber)
                    LviCustomer.SubItems.Add(Client.AccountName)

                    Dim TrAccountsTypess As TextReader = New StreamReader(FiAccountsTypes.FullName)
                    StrAccountsTypes = File.ReadAllText(FiAccountsTypes.FullName)
                    AccountsTypes = JsonSerializer.Deserialize(StrAccountsTypes, GetType(List(Of AccountType)))

                    For Each ActType As AccountType In AccountsTypes
                        If Client.AccountType = ActType.TypeCode Then
                            LviCustomer.SubItems.Add(String.Concat(ActType.TypeCode, " - ", ActType.TypeDecription))
                        End If
                    Next

                    LviCustomer.SubItems.Add(Client.MeterNumber)

                    LviCustomer.SubItems.Add(Client.Address)
                    LviCustomer.SubItems.Add(Client.City)
                    LviCustomer.SubItems.Add(Client.County)
                    LviCustomer.SubItems.Add(Client.State)
                    LviCustomer.SubItems.Add(Client.ZIPCode)
                    LvwCustomers.Items.Add(LviCustomer)
                Next
            End Using
        End If
    End Sub

    Private Sub CustomersCentral_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ShowCustomers()
    End Sub

    Private Sub BtnCreateCustomerAccount_Click(sender As Object, e As EventArgs) Handles BtnCreateCustomerAccount.Click
        Dim Create As CustomersCreate = New CustomersCreate()

        If Create.ShowDialog() = DialogResult.OK Then
            If Create.MtbAccountNumber.Text.Replace("-", "").Trim().Equals("") Then
                MsgBox("You must provide an account number for a new customer. " &
                       "Otherwise, the account cannot be created.",
                       MsgBoxStyle.OkOnly, "Stellar Water Point")
                Exit Sub
            End If

            If Create.MtbMeterNumber.Text.Replace("-", "").Trim().Equals(Nothing) Then
                MsgBox("You must type a valid meter number to associate " &
                       "a water meter to a customer's account. After providing " &
                       "a meter number, click the Find Water Meter button.",
                       MsgBoxStyle.OkOnly, "Stellar Water Point")
                Exit Sub
            End If

            Dim StrCustomers = Nothing
            Dim Clients As List(Of Customer) = New List(Of Customer)
            Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"

            Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)

            If FiCustomers.Exists = True Then
                StrCustomers = File.ReadAllText(FiCustomers.FullName)
                Clients = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))
            End If

            Dim Consumer As Customer = New Customer With {
                .CustomerId = Create.TxtCustomerId.Text,
                .AccountNumber = Create.MtbAccountNumber.Text,
                .AccountName = Create.TxtAccountName.Text,
                .AccountType = Create.CbxAccountsTypes.Text.Substring(0, 3),
                .MeterNumber = Create.MtbMeterNumber.Text,
                .Address = Create.TxtAddress.Text,
                .City = Create.TxtCity.Text,
                .County = Create.TxtCounty.Text,
                .State = Create.TxtState.Text,
                .ZIPCode = Create.MtbZIPCode.Text
            }

            Clients.Add(Consumer)

            Dim options = New JsonSerializerOptions()
            options.WriteIndented = True

            Dim jsCustomers As String = JsonSerializer.Serialize(Clients, GetType(List(Of Customer)), options)
            File.WriteAllText(FiCustomers.FullName, jsCustomers)
        End If

        ShowCustomers()
    End Sub

    Private Sub BtnCustomerAccountDetails_Click(sender As Object, e As EventArgs) Handles BtnCustomerAccountDetails.Click
        Dim Details As CustomersDetails = New CustomersDetails()

        Details.Show()
    End Sub

    Private Sub BtnCustomerAccountEditor_Click(sender As Object, e As EventArgs) Handles BtnCustomerAccountEditor.Click
        Dim Editor As CustomersEditor = New CustomersEditor()

        Editor.ShowDialog()

        ShowCustomers()
    End Sub

    Private Sub BtnDeleteCustomerAccount_Click(sender As Object, e As EventArgs) Handles BtnDeleteCustomerAccount.Click
        Dim Delete As CustomersDelete = New CustomersDelete()

        Delete.ShowDialog()

        ShowCustomers()
    End Sub

    Private Sub BtnClose_Click(sender As Object, e As EventArgs) Handles BtnClose.Click
        Close()
    End Sub
End Class
  12. To execute the application, on the main menu, click Debug -> Start Without Debugging:

    Stellar Water Point

  13. On the Central form, click the Customers button:

    Stellar Water Point - Customers

  14. On the Central form of the customers, click the Delete Customer Account button:

    Stellar Water Point - Water Meter Deletion

  15. In the Account # text box, type 7080-583-5947
  16. Click the Find Customer Account button:

    Stellar Water Point - Customer Account Deletion

  17. Click the Delete Customer Account button

    Stellar Water Point - Customers

  18. Read the text on the message box.
    On the message box, click Yes

    Stellar Water Point - Customers

  19. In the same way, delete the other two records
  20. Close the forms and return to your programming environment
  21. Open the Customers.json file. Replace its contents with the following and save: 
    [
  {
    "CustomerId": 1,
    "AccountNumber": "9279-570-8394",
    "AccountName": "Thomas Stones",
    "MeterNumber": "799-528-461",
    "AccountType": "RES",
    "Address": "10252 Broward Ave #D4",
    "City": "Frederick",
    "County": "Frederick",
    "State": "MD",
    "ZIPCode": "21703-4422"
  },
  {
    "CustomerId": 2,
    "AccountNumber": "4086-938-4783",
    "AccountName": "Bernotte Doughnuts",
    "MeterNumber": "580-742-825",
    "AccountType": "BUS",
    "Address": "10103 Hexagon Drv",
    "City": "Winterstown",
    "County": "York",
    "State": "PA",
    "ZIPCode": "17402-8818"
  },
  {
    "CustomerId": 3,
    "AccountNumber": "2068-258-9486",
    "AccountName": "Yollanda Training",
    "MeterNumber": "186-962-805",
    "AccountType": "UUO",
    "Address": "4819 East Munk Street",
    "City": "Whitehall",
    "County": "Fulton",
    "State": "PA",
    "ZIPCode": "17340-1188"
  },
  {
    "CustomerId": 4,
    "AccountNumber": "6986-829-3741",
    "AccountName": "Eyes Wide",
    "MeterNumber": "208-428-308",
    "AccountType": "BUS",
    "Address": "12087 Avencia Court #4D1",
    "City": "Silver Spring",
    "County": "Montgomery",
    "State": "MD",
    "ZIPCode": "20910-2288"
  },
  {
    "CustomerId": 5,
    "AccountNumber": "9947-374-2648",
    "AccountName": "Marianne Harrington",
    "MeterNumber": "862-715-006",
    "AccountType": "RES",
    "Address": "708 Correta Drv",
    "City": "Arlington",
    "State": "VA",
    "ZIPCode": "22222-6060"
  },
  {
    "CustomerId": 6,
    "AccountNumber": "4293-802-8506",
    "AccountName": "Kelly Davids",
    "MeterNumber": "496-813-794",
    "AccountType": "RES",
    "Address": "938 East Panchot Str",
    "City": "Greenwood",
    "County": "Sussex",
    "State": "DE",
    "ZIPCode": "19950-4242"
  },
  {
    "CustomerId": 7,
    "AccountNumber": "6240-857-4965",
    "AccountName": "First Methodist Congregation",
    "MeterNumber": "739-777-749",
    "AccountType": "RES",
    "Address": "7702 Charles Road",
  },
  {
    "CustomerId": 8,
    "AccountNumber": "7928-131-4850",
    "AccountName": "Department of Public Affairs",
    "AccountType": "SGO",
    "City": "Hyattsville",
    "County": "Prince Georges",
    "State": "MD",
    "ZIPCode": "20783-2277"
  },
  {
    "CustomerId": 9,
    "AccountNumber": "1386-949-2058",
    "AccountName": "Watson Country Buffet",
    "MeterNumber": "296-837-495",
    "AccountType": "WAT",
    "Address": "4862 Wellington Street",
    "City": "Hammonton",
    "County": "Atlantic ",
    "State": "NJ",
    "ZIPCode": "08037-2828"
  },
  {
    "CustomerId": 10,
    "AccountNumber": "7943-686-9786",
    "AccountName": "Angel Bulzaides",
    "MeterNumber": "394-835-297",
    "AccountType": "RES",
    "Address": "10227 Old Harbor Drv",
    "City": "Elkview",
    "County": "Kanawha",
    "State": "WV",
    "ZIPCode": "25071-5858"
  },
  {
    "CustomerId": 11,
    "AccountNumber": "4820-375-2842",
    "AccountName": "Sun Communal",
    "MeterNumber": "392-494-572",
    "AccountType": "SGO",
    "Address": "748 Red Hills Rd",
    "City": "Roanoke",
    "State": "VA",
    "ZIPCode": "24012-4824"
  },
  {
    "CustomerId": 12,
    "AccountNumber": "9618-579-2577",
    "AccountName": "Gerald Place",
    "MeterNumber": "847-252-246",
    "AccountType": "UUO",
    "Address": "3666 Hanchor Drv",
    "City": "Granville",
    "County": "Licking",
    "State": "OH",
    "ZIPCode": "43023-2777"
  },
  {
    "CustomerId": 13,
    "AccountNumber": "",
    "AccountName": ""
  },
  {
    "CustomerId": 14,
    "AccountNumber": "2037-495-8528",
    "AccountName": "Astral Sequence",
    "AccountType": "BUS",
    "Address": "12715 Eastern Gateway",
    "City": "Catonsville",
    "County": "Baltimore County"
  },
  {
    "CustomerId": 15,
    "AccountNumber": "6003-386-3955",
    "AccountName": "Mandiakandara Marmoudi",
    "MeterNumber": "374-886-284",
    "AccountType": "OTH",
    "Address": "539 Avalon Court",
    "City": "Greenwood",
    "County": "Sussex",
    "State": "DE",
    "ZIPCode": "19950-5550"
  },
  {
    "CustomerId": 16,
    "AccountNumber": "5294-859-7513",
    "AccountName": "Jeannette Schiller",
    "MeterNumber": "713-942-058",
    "AccountType": "RES",
    "Address": "10110 Winslow Ave",
    "City": "Mercerville",
    "County": "Mercer",
    "State": "NJ",
    "ZIPCode": "08619-7472"
  },
  {
    "CustomerId": 17,
    "AccountNumber": "9249-379-6848",
    "AccountName": "Country West Eatery",
    "MeterNumber": "588-279-663",
    "AccountType": "BUS",
    "Address": "8280 Sligo North Way",
    "City": "Albright",
    "County": "Preston",
    "State": "WV",
    "ZIPCode": "26519-6620"
  },
  {
    "CustomerId": 18,
    "AccountNumber": "5252-757-9595",
    "AccountName": "Sathyavanthara Khooni",
    "MeterNumber": "379-386-979",
    "AccountType": "RES",
    "Address": "4992 Preston Street",
    "State": "OH"
  },
  {
    "CustomerId": 19,
    "AccountNumber": "7080-583-5947",
    "AccountName": "Sunny Yard",
    "MeterNumber": "827-508-248",
    "AccountType": "WAT",
    "Address": "663 Sherry Wood East Street",
    "City": "Shimpstown",
    "County": "Franklin",
    "State": "PA",
    "ZIPCode": "17236-2626"
  },
  {
    "CustomerId": 20,
    "AccountNumber": "8027-304-6829",
    "AccountName": "Anthony Clarcksons",
    "MeterNumber": "837-806-836",
    "AccountType": "RES",
    "Address": "904 Augusta Drive",
    "City": "Blackbird",
    "County": "New Castle",
    "State": "DE",
    "ZIPCode": "19734-8822"
  },
  {
    "CustomerId": 21,
    "AccountNumber": "6699-396-2905",
    "AccountName": "Spencer Reuter",
    "MeterNumber": "649-373-505",
    "AccountType": "RES",
    "Address": "2850 Burnsweak Avenue",
    "City": "Silver Spring",
    "County": "Montgomery",
    "State": "MD",
    "ZIPCode": "20910-4044"
  },
  {
    "CustomerId": 22,
    "AccountNumber": "1827-395-0203",
    "AccountName": "Watson Country Buffet",
    "MeterNumber": "470-628-850",
    "AccountType": "WAT",
    "Address": "10331 Chryswell Road",
    "City": "Washington",
    "State": "DC",
    "ZIPCode": "20008-2426"
  },
  {
    "CustomerId": 23,
    "AccountNumber": "5862-736-9741",
    "AccountName": "Eastern Cage",

    "AccountType": "BUS",
    "Address": "2039 Night Stand Court",
    "City": "Hammonton",
    "State": "NJ"
  },
  {
    "CustomerId": 24,
    "AccountNumber": "3947-957-4958",
    "AccountName": "Patsil Industries",
    "MeterNumber": "747-581-379",
    "AccountType": "BUS",
    "Address": "10348 Larrens Drive",
    "City": "Baltimore",
    "County": "Baltimore",
    "State": "MD",
    "ZIPCode": "21215-2222"
  },
  {
    "CustomerId": 25,
    "AccountNumber": "2836-485-9699",
    "AccountName": "Red Oak High School",
    "MeterNumber": "379-386-979",
    "AccountType": "SGO",
    "Address": "442 Donham Road",
    "City": "Silver Spring",
    "County": "Montgomery",
    "State": "MD",
    "ZIPCode": "20910-8822"
  },
  {
    "CustomerId": 26,
    "AccountNumber": "5938-074-5293",
    "AccountName": "Park and Roll",
    "MeterNumber": "592-824-957",
    "AccountType": "SGO",
    "Address": "582G Dunhill Avenue",
    "City": "Lanham",
    "County": "Prince Georges",
    "State": "MD",
    "ZIPCode": "20706-8284"
  },
  {
    "CustomerId": 27,
    "AccountNumber": "3028-502-9418",
    "AccountName": "Spencer Kershaw",
    "MeterNumber": "186-959-757",
    "AccountType": "RES",
    "Address": "338C Grayson Street",
    "City": "Gatchellville",
    "County": "York",
    "State": "PA",
    "ZIPCode": "17352-6464"
  },
  {
    "CustomerId": 28,
    "AccountNumber": "9684-759-2227",
    "AccountName": "Country West Eatery",
    "MeterNumber": "928-317-924",
    "AccountType": "BUS"
  },
  {
    "CustomerId": 29,
    "AccountNumber": "2974-972-8139",
    "AccountName": "Paul Arnette",
    "MeterNumber": "295-770-695",
    "AccountType": "OTH",
    "Address": "8127 Bledsoe Str",
    "City": "Hyattsville",
    "County": "Prince Georges",
    "State": "MD",
    "ZIPCode": "20783-5858"
  },
  {
    "CustomerId": 30,
    "AccountNumber": "2758-493-7249",
    "AccountName": "Hervey Smile",
    "MeterNumber": "293-924-869",
    "AccountType": "WAT",
    "Address": "12973 Sonaa Street #E42",
    "City": "Silver Spring",
    "County": "Montgomery",
    "State": "MD",
    "ZIPCode": "20910-4488"
  },
  {
    "CustomerId": 31,
    "AccountNumber": "9337-947-3664",
    "AccountName": "Awesome Aid",
    "MeterNumber": "649-358-184",
    "AccountType": "SGO",
    "City": "Bellefontaine",
    "State": "OH"
  },
  {
    "CustomerId": 32,
    "AccountNumber": "7518-302-6895",
    "AccountName": "Grace Brenner",
    "MeterNumber": "207-964-835",
    "AccountType": "BUS",
    "Address": "4299 Peachtree Court",
    "City": "Rockville",
    "County": "Montgomery",
    "State": "MD",
    "ZIPCode": "20853-1888"
  },
  {
    "CustomerId": 33,
    "AccountNumber": "2937-947-3008",
    "AccountName": "Jeffrey Maney",
    "AccountType": "RES"
  },
  {
    "CustomerId": 34,
    "AccountNumber": "7028-405-9381",
    "AccountName": "Valley Services",
    "MeterNumber": "306-842-497",
    "AccountType": "WAT",
    "Address": "613 Meadowhill Road",
    "City": "Alonzaville",
    "County": "Shenandoah",
    "State": "VA",
    "ZIPCode": "22664-8080"
  },
  {
    "CustomerId": 35,
    "AccountNumber": "5293-957-3395",
    "AccountName": "Wellway Community Center",
    "MeterNumber": "386-468-057",
    "AccountType": "RES",
    "Address": "10484 Greenway Avenue",
    "City": "Mt Storm",
    "County": "Grant",
    "State": "WV",
    "ZIPCode": "26739-7700"
  },
  {
    "CustomerId": 36,
    "AccountNumber": "2038-413-9680",
    "AccountName": "Eastern Friandise",
    "MeterNumber": "938-725-869",
    "AccountType": "BUS",
    "Address": "2075 Rose Hills Avenue",
    "City": "Washington",
    "State": "DC",
    "ZIPCode": "20004-2626"
  },
  {
    "CustomerId": 37,
    "AccountNumber": "7484-744-9708",
    "AccountName": "Amidou Gomah",
    "AccountType": "RES",
    "Address": "14118 Yellow Burrough Blvd",
    "City": "Philadelphia",
    "State": "PA"
  },
  {
    "CustomerId": 38,
    "AccountNumber": "3792-853-6885",
    "AccountName": "Department of Public Affairs",
    "MeterNumber": "595-753-147",
    "City": "Upper Marlboro",
    "County": "Prince George County"
  },
  {
    "CustomerId": 39,
    "AccountNumber": "8282-777-8282",
    "AccountName": "Garland Hotel",
    "MeterNumber": "938-275-294",
    "AccountType": "BUS",
    "Address": "4222 Extell Ave",
    "City": "Cambridge",
    "State": "MD",
    "ZIPCode": "21613-2288"
  },
  {
    "CustomerId": 40,
    "AccountNumber": "5975-863-7057",
    "AccountName": "Single Connection",
    "MeterNumber": "288-427-585",
    "AccountType": "BUS",
    "City": "Mansfield",
    "State": "OH",
    "ZIPCode": "44903-3030"
  },
  {
    "CustomerId": 41,
    "AccountNumber": "2499-636-4444",
    "AccountName": "Bryanna Spencer",
    "AccountType": "RES",
    "Address": "6282 Sheppherd Str",
    "County": "Anne Arundel"
  },
  {
    "CustomerId": 42,
    "AccountNumber": "2842-585-7260",
    "AccountName": "District Community Reserves",
    "MeterNumber": "349-725-848",
    "AccountType": "SGO",
    "Address": "3280 Hopewell Street, NE",
    "City": "Washington"
  },
  {
    "CustomerId": 43,
    "AccountNumber": "9282-794-7937",
    "AccountName": "Yashua Yáñés",
    "MeterNumber": "392-494-572",
    "AccountType": "RES",
    "Address": "10214 Monroe Ave",
    "City": "Easton",
    "State": "MD"
  },
  {
    "CustomerId": 44,
    "AccountNumber": "6837-468-4750",
    "AccountName": "Miguel Altieri",
    "AccountType": "RES",
    "Address": "10941 Patriot Blvd",
    "City": "Crenshaw",
    "County": "Jefferson",
    "State": "PA",
    "ZIPCode": "15824-6628"
  },
  {
    "CustomerId": 45,
    "AccountNumber": "2847-597-2829",
    "AccountName": "Jameson",
    "MeterNumber": "379-386-979",
    "AccountType": "WAT",
    "Address": "7373 Gold Town Rd",
    "State": "WV"
  },
  {
    "CustomerId": 46,
    "AccountNumber": "6381-748-2222",
    "AccountName": "Up Eyes",
    "AccountType": "BUS",
    "Address": "4149 Deerfield Str"
  },
  {
    "CustomerId": 47,
    "AccountNumber": "4968-274-9638",
    "AccountName": "Annette Wald",
    "AccountType": "RES",
    "Address": "11441  Eastern Friendshi Rd"
  },
  {
    "CustomerId": 48,
    "AccountNumber": "8384-708-2941",
    "AccountName": "Department of Environment Affairs",
    "AccountType": "SGO",
    "State": "OH"
  },
  {
    "CustomerId": 49,
    "AccountNumber": "3728-138-2947",
    "AccountName": "Marie Rath",
    "Address": "8802 Atlantic Ave",
    "State": "PA"
  },
  {
    "CustomerId": 50,
    "AccountNumber": "1793-857-9413",
    "AccountName": "Body Care",
    "AccountType": "WAT",
    "City": "Ocean City",
    "State": "NJ"
  },
  {
    "CustomerId": 51,
    "AccountNumber": "6028-695-2068",
    "AccountName": "Ronald Glassman",
    "MeterNumber": "468-359-486",
    "AccountType": "BUS",
  },
  {
    "CustomerId": 52,
    "AccountNumber": "4069-37-49728",
    "AccountName": "Lucette Wash N Dry",
    "AccountType": "WAT",
    "Address": "8812 Lawrence Ave",
    "State": "NW"
  },
  {
    "CustomerId": 53,
    "AccountNumber": "9616-283-7249",
    "AccountName": "Department of Public Affairs",
    "AccountType": "SGO",
    "Address": "13006 Blueberry Ave",
    "City": "Greenbelt",
    "State": "MD",
    "ZIPCode": "20770-2040"
  },
  {
    "CustomerId": 54,
    "AccountNumber": "2829-516-8353",
    "AccountName": "Richard Eghert",
    "AccountType": "RES",
    "Address": "662 Placido Road"
  },
  {
    "CustomerId": 55,
    "AccountNumber": "6296-875-9607",
    "AccountName": "Country West Eatery",
    "AccountType": "BUS",
    "Address": "837 Larrenson Drv",
    "City": "Cumberland",
    "State": "MD"
  },
  {
    "CustomerId": 56,
    "AccountNumber": "9684-794-6379",
    "AccountName": "Eye Care",
    "AccountType": "BUS",
    "Address": "8626 Cameron Str"
  },
  {
    "CustomerId": 57,
    "AccountNumber": "2405-839-5820",
    "AccountName": "Watson Country Buffet",
    "AccountType": "WAT",
    "City": "Harrisburg",
    "State": "PA"
  }
]

Water Bills

Introduction

A water bill is an intermediary document between the water distribution company and a consumer. We will create the classes, forms, and operations to present that information.

Practical LearningPractical Learning: Introducing Water Bills

  1. To create a class, in the Solution Explorer, right-click Models -> Add -> Class...
  2. Type WaterBill as the Name of the file
  3. Click Add
  4. Define the class as follows: 
    Public Class WaterBill
    Public Property WaterBillId As Integer
    Public Property BillNumber As Integer
    Public Property AccountNumber As String
    Public Property MeterReadingStartDate As Date
    Public Property MeterReadingEndDate As Date
    Public Property BillingDays As Integer
    Public Property CounterReadingStart As Integer
    Public Property CounterReadingEnd As Integer
    Public Property TotalHCF As Integer
    Public Property TotalGallons As Integer
    Public Property FirstTierConsumption As Double
    Public Property SecondTierConsumption As Double
    Public Property LastTierConsumption As Double
    Public Property WaterCharges As Double
    Public Property SewerCharges As Double
    Public Property EnvironmentCharges As Double
    Public Property ServiceCharges As Double
    Public Property TotalCharges As Double
    Public Property StateTaxes As Double
    Public Property LocalTaxes As Double
    Public Property PaymentDueDate As Date
    Public Property AmountDue As Double
    Public Property LatePaymentDueDate As Date
    Public Property LateAmountDue As Double
End Class
  5. To create another class, in the Solution Explorer, right-click Models -> Add -> Class...
  6. Type WaterBillManager as the Name of the file
  7. Click Add
  8. Define the class as follows: 
    Friend Class WaterBillManager
    Friend Shared Function CalculateTiers(Acnt As String, Total As Double) As (a As Double, b As Double, c As Double)
        Dim Results As (Tier1 As Double, Tier2 As Double, Tier3 As Double) = (0.00, 0.00, 0.00)

        Select Case Acnt
            Case "RES"
                Results.Tier1 = Total * 39.35 / 10000.0
                Results.Tier2 = Total * 18.25 / 10000.0
                Results.Tier3 = Total * 11.65 / 10000.0

            Case "SGO"
                Results.Tier1 = Total * 41.38 / 10000.0
                Results.Tier2 = Total * 15.26 / 10000.0
                Results.Tier3 = Total * 8.13 / 10000.0

            Case "BUS"
                Results.Tier1 = Total * 51.25 / 10000.0
                Results.Tier2 = Total * 34.65 / 10000.0
                Results.Tier3 = Total * 15.1 / 10000.0

            Case "UUO"
                Results.Tier1 = Total * 25.0 / 10000.0
                Results.Tier2 = Total * 35.0 / 10000.0
                Results.Tier3 = Total * 40.0 / 10000.0

            Case "WAT"
                Results.Tier1 = (Total / 6) * 3 * 50.0 / 10000.0
                Results.Tier2 = (Total / 6) * 2 * 35.0 / 10000.0
                Results.Tier3 = Total * 15.0 / 10000.0
            Case Else
                Results.Tier1 = Total * (48.0 / 10000.0)
                Results.Tier2 = Total * (32.0 / 10000.0)
                Results.Tier3 = Total * (20.0 / 10000.0)
        End Select

        Return Results
    End Function

    Friend Shared Function CalculateSewerCharges(Acnt As String, Total As Double) As Double
        Dim Result As Double

        If Acnt = "RES" Then
            Result = Total * 1.028641 / 100.0
        ElseIf Acnt = "SGO" Then
            Result = Total * 4.162522 / 100.0
        ElseIf Acnt = "BUS" Then
            Result = Total * 8.446369 / 100.0
        ElseIf Acnt = "UUO" Then
            Result = Total * 10.622471 / 100.0
        ElseIf Acnt = "WAT" Then
            Result = Total * 12.053152 / 100.0
        Else ' if acnt = "OTH" then
            Result = Total * 9.206252 / 100.0
        End If

        Return Result
    End Function

    Friend Shared Function CalculateEnvironmentCharges(Acnt As String, Total As Double) As Double
        Dim Result As Double

        Select Case Acnt
            Case "RES"
                Result = Total * 0.004524

            Case "SGO"
                Result = Total * 0.118242

            Case "BUS"
                Result = Total * 0.161369

            Case "UUO"
                Result = Total * 0.082477

            Case "WAT"
                Result = Total * 0.413574

            Case Else
                Result = Total * 0.221842

        End Select

        Return Result
    End Function

    Friend Shared Function CalculateServiceCharges(Acnt As String, Total As Double) As Double
        Select Case Acnt
            Case "RES"
                Return Total * 0.006248
            Case "SGO"
                Return Total * 0.102246
            Case "BUS"
                Return Total * 0.155227
            Case "UUO"
                Return Total * 0.186692
            Case "WAT"
                Return Total * 0.412628
            Case Else
                Return Total * 0.210248
        End Select
    End Function

    Friend Shared Function CalculateLocalTaxes(Acnt As String, Total As Double) As Double
        Select Case Acnt
            Case "RES"
                Return Total * 0.035749
            Case "SGO"
                Return Total * 0.044026
            Case "BUS"
                Return Total * 0.122517
            Case "UUO"
                Return Total * 0.105737
            Case "WAT"
                Return Total * 0.153248
            Case Else
                Return Total * 0.125148
        End Select
    End Function

    Friend Shared Function CalculateStateTaxes(Acnt As String, Total As Double) As Double
        Select Case Acnt
            Case "RES"
                Return Total * 0.007124
            Case "SGO"
                Return Total * 0.008779
            Case "BUS"
                Return Total * 0.042448
            Case "UUO"
                Return Total * 0.067958
            Case "WAT"
                Return Total * 0.081622
            Case Else
                Return Total * 0.013746
        End Select
    End Function

    Friend Shared Function SetPaymentDueDate(Acnt As String, Dt As Date) As Date
        Dim TsPaymentDueDate As TimeSpan = New TimeSpan(1, 0, 0, 0)

        If Acnt = "RES" Then
            TsPaymentDueDate = New TimeSpan(15, 0, 0, 0)
        ElseIf Acnt = "SGO" Then
            TsPaymentDueDate = New TimeSpan(20, 0, 0, 0)
        ElseIf Acnt = "BUS" Then
            TsPaymentDueDate = New TimeSpan(30, 0, 0, 0)
        ElseIf Acnt = "UUO" Then
            TsPaymentDueDate = New TimeSpan(15, 0, 0, 0)
        ElseIf Acnt = "WAT" Then
            TsPaymentDueDate = New TimeSpan(40, 0, 0, 0)
        Else
            TsPaymentDueDate = New TimeSpan(35, 0, 0, 0)
        End If

        Return Dt + TsPaymentDueDate
    End Function

    Friend Shared Function SetLatePaymentDueDate(Acnt As String, Dt As Date) As Date
        Select Case Acnt
            Case "RES"
                Return Dt + New TimeSpan(30, 0, 0, 0)
            Case "SGO"
                Return Dt + New TimeSpan(40, 0, 0, 0)
            Case "BUS"
                Return Dt + New TimeSpan(50, 0, 0, 0)
            Case "UUO"
                Return Dt + New TimeSpan(60, 0, 0, 0)
            Case "WAT"
                Return Dt + New TimeSpan(65, 0, 0, 0)
            Case Else
                Return Dt + New TimeSpan(45, 0, 0, 0)
        End Select
    End Function

    Friend Shared Function CalculateLateAmountDue(Acnt As String, Amt As Double) As Double
        Select Case Acnt
            Case "RES"
                Return Amt + 8.95
            Case "SGO"
                Return Amt + (Amt / 4.575)
            Case "BUS"
                Return Amt + (Amt / 12.315)
            Case "UUO"
                Return Amt + (Amt / 7.425)
            Case "WAT"
                Return Amt + (Amt / 15.225)
            Case Else
                Return Amt + (Amt / 6.735)
        End Select
    End Function
End Class

Showing Water Bills

A water distribution company has many records for water bills, and a typical water bill includes many pieces of information. We will create a form that displays a list of some pieces of information about a water bill.

Practical LearningPractical Learning: Showing Water Bills

  1. To create a form, in the Solution Explorer, right-click WaterBills -> Add -> Form (Windows Forms)...
  2. For the Name of the form, type Central
  3. Click Add
  4. In the Toolbox, click the ListView button and click the form
  5. On the form, right-click the list view and click Edit Columns...
  6. Create the columns as follows:
    (Name) Text TextAlign Width
    ColWaterBillId Id   40
    ColBillNumber Bill # Center 80
    ColAccountSummary Account Summary   550
    ColStartDate Start Date Center 150
    ColEndDate End Date Center 150
    ColBillingDays Days Center  
    ColCounterStart Counter Start Right 125
    ColCounterEnd Counter End Right 125
    ColTotalHCF Total HCF Right 100
    ColGallons Gallons Right 95
    ColPaymentDueDate Pmt Due Date Center 125
    ColAmountDue Amt Due Right 90
  7. Click OK
  8. Position and resize the list view on the form as follows:

    Stellar Water Point - Water Bills

    Control (Name) Other Properties
    ListView List View LvwWaterBills FullRowSelect: True
    GridLines: True
    View: Details
  9. Right-click an area of the form and click View Code
  10. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class WaterBillsCentral
    Private Sub ShowWaterBills()
        Dim StrCustomers = Nothing
        Dim StrWaterBills = Nothing
        Dim StrAccountsTypes = Nothing

        Dim AccountsTypes = New List(Of AccountType)
        Dim Clients As List(Of Customer) = New List(Of Customer)
        Dim WaterBills As List(Of WaterBill) = New List(Of WaterBill)

        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"
        Dim FileAccountsTypes = "C:\Stellar Water Point16\AccountsTypes.json"
        Dim FileWaterBills As String = "C:\Stellar Water Point16\WaterBills.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)
        Dim FiWaterBills As FileInfo = New FileInfo(FileWaterBills)
        Dim FiAccountsTypes As FileInfo = New FileInfo(FileAccountsTypes)

        If FiCustomers.Exists = True Then
            Using TrCustomers As TextReader = New StreamReader(FiCustomers.FullName)
                StrCustomers = File.ReadAllText(FiCustomers.FullName)

                Clients = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))
            End Using
        End If

        Dim TrAccountsTypess As TextReader = New StreamReader(FiAccountsTypes.FullName)
        StrAccountsTypes = File.ReadAllText(FiAccountsTypes.FullName)
        AccountsTypes = JsonSerializer.Deserialize(StrAccountsTypes, GetType(List(Of AccountType)))

        Dim StrAccountSummary As String

        If FiWaterBills.Exists = True Then
            Using TrWaterBills As TextReader = New StreamReader(FiWaterBills.FullName)
                StrWaterBills = File.ReadAllText(FiWaterBills.FullName)

                WaterBills = JsonSerializer.Deserialize(StrWaterBills, GetType(List(Of WaterBill)))

                LvwWaterBills.Items.Clear()

                For Each Invoice As WaterBill In WaterBills
                    Dim LviWaterBill As ListViewItem = New ListViewItem(Invoice.WaterBillId)

                    LviWaterBill.SubItems.Add(Invoice.BillNumber)

                    Dim Client As IEnumerable(Of Customer) = Clients.Where(Function(Cust) Cust.AccountNumber = Invoice.AccountNumber)

                    StrAccountSummary = Invoice.AccountNumber

                    For Each Cust In Clients
                        If Cust.AccountNumber = Invoice.AccountNumber Then

                            For Each ActType As AccountType In AccountsTypes
                                If Cust.AccountType = ActType.TypeCode Then
                                    StrAccountSummary = StrAccountSummary & " - " &
                                                        Cust.AccountName & ", Acnt Type: " & String.Concat(ActType.TypeCode, " - ", ActType.TypeDecription) &
                                                        ", (Mtr #: " & Cust.MeterNumber & ")"
                                End If
                            Next
                        End If
                    Next

                    For Each Cust As Customer In Clients
                        LviWaterBill.SubItems.Add(StrAccountSummary)

                        LviWaterBill.SubItems.Add(Invoice.MeterReadingStartDate.ToShortDateString())
                        LviWaterBill.SubItems.Add(Invoice.MeterReadingEndDate.ToShortDateString())
                        LviWaterBill.SubItems.Add(Invoice.BillingDays)
                        LviWaterBill.SubItems.Add(Invoice.CounterReadingStart)
                        LviWaterBill.SubItems.Add(Invoice.CounterReadingEnd)
                        LviWaterBill.SubItems.Add(Invoice.TotalHCF)
                        LviWaterBill.SubItems.Add(Invoice.TotalGallons)
                        LviWaterBill.SubItems.Add(Invoice.PaymentDueDate.ToShortDateString())
                        LviWaterBill.SubItems.Add(Invoice.AmountDue)
                    Next

                    LvwWaterBills.Items.Add(LviWaterBill)
                Next
            End Using
        End If
    End Sub

    Private Sub WaterBillsCentral_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ShowWaterBills()
    End Sub
End Class
  11. In the Solution Explorer, double-click WaterDistribution.vb to display the main form of the application
  12. From the Toolbox, add two buttons to the form
  13. From the Properties window, change the characteristics of the button as follows:

    Stellar Water Point

    Control (Name) Text Font
    Button Button BtnWaterBills C&Water Bills... Times New Roman, 24pt, style=Bold
    Button Button BtnClose &Close Times New Roman, 24pt, style=Bold
  14. Right-click any area of the form and click View Code
  15. Impliment an event for the new button as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class WaterDistribution
    Private Sub CreateWaterMeters()
        . . .

    End Sub

    Private Sub CreateAccountsTypes()
        . . .
    End Sub
    Private Sub WaterDistribution_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        REM Directory.CreateDirectory("C:\Stellar Water Point16")

        REM CreateWaterMeters()
        REM CreateAccountsTypes()
    End Sub

    Private Sub BtnWaterBills_Click(sender As Object, e As EventArgs) Handles BtnWaterBills.Click
        Dim Central = New WaterBillsCentral()

        Central.Show()
    End Sub

    Private Sub BtnCustomers_Click(sender As Object, e As EventArgs) Handles BtnCustomers.Click
        Dim Central = New CustomersCentral

        Central.Show()
    End Sub

    Private Sub BtnWaterMeters_Click(sender As Object, e As EventArgs) Handles BtnWaterMeters.Click
        Dim Central = New WaterMetersCentral()

        Central.Show()
    End Sub

    Private Sub BtnClose_Click(sender As Object, e As EventArgs) Handles BtnClose.Click
        Close()
    End Sub
End Class

A New Water Bill

A water is probably the most important aspect of water distribution. We will provide a form that allows an employee to register the information necessary for water consumption. Then we will perform some operations. Finally, we will present the amount the consumer should pay and when.

Practical LearningPractical Learning: Processing a Water Bill

  1. To create a form, in the Solution Explorer, right-click WaterBills -> Add -> Form (Windows Forms)...
  2. Set the name to Create
  3. Click Add
  4. Design the form as follows:

    Stellar Water Point - New Water Bill

    Control Text Name Other Properties
    Label Label &Water Bill #:    
    TextBox Text Box   TxtBillNumber  
    GroupBox Group Box Customer Information    
    Label Label &Account #:    
    MaskedTextBox Masked Text Box   MtbAccountNumber Mask: 0000-000-0000
    Button Button Find Customer &Account BtnFindCustomerAccount  
    Label Label Account Name:    
    TextBox Text Box   TxtAccountName  
    Label Label Account Type:    
    TextBox Text Box   TxtAccountType  
    Label Label Address:    
    TextBox Text Box   TxtAddress  
    TextBox Text Box   TxtCity  
    TextBox Text Box   TxtCounty  
    TextBox Text Box   TxtState  
    TextBox Text Box   TxtZIPCode  
    Label Label ___________________________    
    Label Label Meter Details:    
    TextBox Text Box   TxtMeterDetails  
    GroupBox Group Box Meter Reading    
    Label Label Meter &Reading Start Date:    
    Date Time Picker Text Box   DtpMeterReadingStartDate  
    Label Label Meter Reading &End Date:    
    Date Time Picker Text Box   DtpMeterReadingEndDate  
    Label Label Coun&ter Reading Start:    
    TextBox Text Box   TxtCounterReadingStart  
    Label Label Counter Readi&ng End:    
    TextBox Text Box   TxtCounterReadingEnd  
    Button Button &Evaluate Water Bill BtnEvaluateWaterBill Times New Roman, 24pt, style=Bold
    GroupBox Group Box Meter Result    
    Label Label Billing Days:    
    TextBox Text Box   TxtBillingDays  
    Label Label Total HCF:    
    TextBox Text Box   TxtTotalHCF  
    Label Label Total Gallons:    
    TextBox Text Box   TxtTotalGallons  
    Label Label First Tier Consumption:    
    TextBox Text Box   TxtFirstTierConsumption  
    Label Label Second Tier:    
    TextBox Text Box   TxtSecondTierConsumption  
    Label Label Last Tier:    
    TextBox Text Box   TxtLastTierConsumption  
    GroupBox Group Box Consumption Charges    
    Label Label Water Charges:    
    TextBox Text Box   TxtWaterCharges  
    Label Label Sewer Charges:    
    TextBox Text Box   TxtSewerCharges  
    Label Label Environment Charges:    
    TextBox Text Box   TxtEnvironmentCharges  
    Label Label Service Charges:    
    TextBox Text Box   TxtServiceCharges  
    Label Label Total Charges:    
    TextBox Text Box   TxtTotalCharges  
    GroupBox Group Box Taxes    
    Label Label Local Taxes:    
    TextBox Text Box   TxtLocalTaxes  
    Label Label State Taxes:    
    TextBox Text Box   TxtStateTaxes  
    GroupBox Group Box Water Bill Payment    
    Label Label Payment Due Date:    
    Date Time Picker Text Box   dtpPaymentDueDate  
    Label Label Amount Due:    
    TextBox Text Box   TxtAmountDue  
    Label Label Late Payment Due Date:    
    Date Time Picker Text Box   dtpLatePaymentDueDate  
    Label Label &Late Amount Due:    
    TextBox Text Box   TxtLateAmountDue  
    Label Label Water Bill Id:&    
    TextBox Text Box   TxtWaterBillId  
    Button Button Save Water Bill BtnSaveWaterBill  
    Button Button &Close BtnClose  

    Form Properties

    Form Property Value
    FormBorderStyle FixedDialog
    Text Stellar Water Point - Water Bill Processing
    StartPosition CenterScreen
    MaximizeBox False
    MinimizeBox False
  5. Right-click an area of the form and click View Code
  6. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class WaterBillsCreate
    Private Sub WaterBillsCreate_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim StrWaterBills = Nothing
        Dim WaterBills As List(Of WaterBill) = New List(Of WaterBill)
        Dim fileWaterBills As String = "C:\Stellar Water Point16\WaterBills.json"

        Dim FiWaterBills As FileInfo = New FileInfo(fileWaterBills)

        Dim waterBillId = 0

        If FiWaterBills.Exists = True Then
            Using TrWaterBills As TextReader = New StreamReader(FiWaterBills.FullName)
                StrWaterBills = File.ReadAllText(FiWaterBills.FullName)
                WaterBills = JsonSerializer.Deserialize(StrWaterBills, GetType(List(Of WaterBill)))

                For Each Bill As WaterBill In WaterBills
                    waterBillId = Bill.WaterBillId
                Next
            End Using
        End If

        TxtWaterBillId.Text = CStr(waterBillId + 1)
    End Sub

    Private Sub BtnFindCustomerAccount_Click(sender As Object, e As EventArgs) Handles BtnFindCustomerAccount.Click
        If String.IsNullOrEmpty(MtbAccountNumber.Text) Then
            MsgBox("You must type a valid account number of a customer, " &
                   "and then click the Find Customer Account button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrCustomers = Nothing
        Dim StrAccountsTypes = Nothing
        Dim AccountsTypes = New List(Of AccountType)
        Dim Clients As List(Of Customer) = New List(Of Customer)
        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"
        Dim FileAccountsTypes = "C:\Stellar Water Point16\AccountsTypes.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)
        Dim FiAccountsTypes As FileInfo = New FileInfo(FileAccountsTypes)

        Dim StrMeterNumber = Nothing

        If FiCustomers.Exists = True Then
            Using TrCustomers As TextReader = New StreamReader(FiCustomers.FullName)
                StrCustomers = File.ReadAllText(FiCustomers.FullName)
                Clients = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))

                Dim customers As IEnumerable(Of Customer) = Clients.Where(Function(Client) Client.AccountNumber = MtbAccountNumber.Text)

                For Each Client As Customer In customers
                    TxtAccountName.Text = Client.AccountName
                    StrMeterNumber = Client.MeterNumber

                    Dim TrAccountsTypess As TextReader = New StreamReader(FiAccountsTypes.FullName)
                    StrAccountsTypes = File.ReadAllText(FiAccountsTypes.FullName)
                    AccountsTypes = JsonSerializer.Deserialize(StrAccountsTypes, GetType(List(Of AccountType)))

                    For Each ActType As AccountType In AccountsTypes
                        If Client.AccountType = ActType.TypeCode Then
                            TxtAccountType.Text = String.Concat(ActType.TypeCode, " - ", ActType.TypeDecription)
                        End If
                    Next

                    TxtAddress.Text = Client.Address
                        TxtCity.Text = Client.City
                        TxtCounty.Text = Client.County
                        TxtState.Text = Client.State
                        TxtZIPCode.Text = Client.ZIPCode
                    Next
            End Using
        End If

        If Len(StrMeterNumber) > 0 Then
            Dim StrWaterMeters As String = Nothing
            Dim WaterMeters As List(Of WaterMeter) = New List(Of WaterMeter)
            Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

            Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

            If FiWaterMeters.Exists = True Then
                StrWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
                WaterMeters = JsonSerializer.Deserialize(StrWaterMeters, GetType(List(Of WaterMeter)))

                Dim Meters As IEnumerable(Of WaterMeter) = WaterMeters.Where(Function(Mtr) Mtr.MeterNumber = StrMeterNumber)

                For Each Meter As WaterMeter In Meters
                    TxtMeterDetails.Text = Meter.WaterMeterId & " - " &
                                           Meter.Make & " " &
                                           Meter.Model &
                                           " (Meter Size: " & Meter.MeterSize & ")"
                Next
            End If
        End If
    End Sub

    Private Sub DtpMeterReadingEndDate_ValueChanged(sender As Object, e As EventArgs) Handles DtpMeterReadingEndDate.ValueChanged
        TxtBillingDays.Text = DateDiff(DateInterval.Day, DtpMeterReadingStartDate.Value, DtpMeterReadingEndDate.Value) + 1
    End Sub

    Private Sub BtnEvaluateWaterBill_Click(sender As Object, e As EventArgs) Handles BtnEvaluateWaterBill.Click
        Dim CounterStart As Double = 0, CounterEnd = 0

        Try
            CounterStart = CDbl(TxtCounterReadingStart.Text)
        Catch FeCRStart As FormatException
            MsgBox("You must enter a valid value in the Counter Reading Start text box. " &
                   "The error produced is: " & FeCRStart.Message,
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
        End Try

        Try
            counterEnd = CDbl(TxtCounterReadingEnd.Text)
        Catch FeCREnd As FormatException
            MsgBox("You must enter a valid value in the Counter Reading End text box. " &
                   "The error produced is: " & FeCREnd.Message,
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
        End Try

        Dim Consumption As Double = CounterEnd - CounterStart
        Dim Gallons As Double = Consumption * 748.05
        Dim StrAccountType As String = TxtAccountType.Text.Substring(1, 3)

        Dim Tiers As (first As Double, second As Double, last As Double) = WaterBillManager.CalculateTiers(strAccountType, gallons)

        Dim WaterCharges = Tiers.first + Tiers.second + Tiers.last
        Dim SewerCharges = WaterBillManager.CalculateSewerCharges(StrAccountType, WaterCharges)
        Dim EnvCharges = WaterBillManager.CalculateEnvironmentCharges(StrAccountType, WaterCharges)
        Dim SrvCharges = WaterBillManager.CalculateServiceCharges(StrAccountType, WaterCharges)
        Dim TotalCharges = WaterCharges + SewerCharges + EnvCharges + SrvCharges
        Dim LocalTaxes = WaterBillManager.CalculateLocalTaxes(StrAccountType, WaterCharges)
        Dim StateTaxes = WaterBillManager.CalculateStateTaxes(StrAccountType, WaterCharges)
        Dim AmtDue = TotalCharges + LocalTaxes + StateTaxes

        TxtTotalHCF.Text = consumption.ToString()
        TxtTotalGallons.Text = Math.Ceiling(Gallons)
        TxtFirstTierConsumption.Text = FormatNumber(Tiers.first)
        TxtSecondTierConsumption.Text = FormatNumber(Tiers.second)
        TxtLastTierConsumption.Text = FormatNumber(Tiers.last)
        TxtWaterCharges.Text = FormatNumber(WaterCharges)
        TxtSewerCharges.Text = FormatNumber(SewerCharges)
        TxtEnvironmentCharges.Text = FormatNumber(EnvCharges)
        TxtServiceCharges.Text = FormatNumber(SrvCharges)
        TxtTotalCharges.Text = FormatNumber(TotalCharges)
        TxtLocalTaxes.Text = FormatNumber(LocalTaxes)
        TxtStateTaxes.Text = FormatNumber(StateTaxes)
        DtpPaymentDueDate.Value = WaterBillManager.SetPaymentDueDate(strAccountType, dtpMeterReadingEndDate.Value)
        TxtAmountDue.Text = FormatNumber(AmtDue)
        DtpLatePaymentDueDate.Value = WaterBillManager.SetLatePaymentDueDate(strAccountType, dtpMeterReadingEndDate.Value)
        TxtLateAmountDue.Text = FormatNumber(WaterBillManager.CalculateLateAmountDue(StrAccountType, AmtDue))
    End Sub

    Private Sub BtnSaveWaterBill_Click(sender As Object, e As EventArgs) Handles BtnSaveWaterBill.Click
        If String.IsNullOrEmpty(TxtWaterBillNumber.Text) Then
            MsgBox("You must type a (unique) bill number for the " &
                   "water bill you are processing.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        If String.IsNullOrEmpty(MtbAccountNumber.Text) Then
            MsgBox("You must specify the account number of the customer " &
                   "whose water bill you are preparing.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrWaterBills As String = Nothing
        Dim WaterBills As List(Of WaterBill) = New List(Of WaterBill)
        Dim FileWaterBills As String = "C:\Stellar Water Point16\WaterBills.json"

        Dim FiWaterBills As FileInfo = New FileInfo(FileWaterBills)

        If FiWaterBills.Exists = True Then
            StrWaterBills = File.ReadAllText(FiWaterBills.FullName)
            WaterBills = JsonSerializer.Deserialize(StrWaterBills, GetType(List(Of WaterBill)))
        End If

        Dim Bill As WaterBill = New WaterBill() With
        {
        .WaterBillId = TxtWaterBillId.Text,
            .BillNumber = TxtWaterBillNumber.Text,
 .AccountNumber = MtbAccountNumber.Text,
  .MeterReadingStartDate = DtpMeterReadingStartDate.Value,
   .MeterReadingEndDate = DtpMeterReadingEndDate.Value,
    .BillingDays = TxtBillingDays.Text,
     .CounterReadingStart = TxtCounterReadingStart.Text,
      .CounterReadingEnd = TxtCounterReadingEnd.Text,
       .TotalHCF = TxtTotalHCF.Text,
        .TotalGallons = TxtTotalGallons.Text,
         .FirstTierConsumption = TxtFirstTierConsumption.Text,
          .SecondTierConsumption = TxtSecondTierConsumption.Text,
           .LastTierConsumption = TxtLastTierConsumption.Text,
            .WaterCharges = TxtWaterCharges.Text,
             .SewerCharges = TxtSewerCharges.Text,
              .EnvironmentCharges = TxtEnvironmentCharges.Text,
               .ServiceCharges = TxtServiceCharges.Text,
                .TotalCharges = TxtTotalCharges.Text,
     .LocalTaxes = TxtLocalTaxes.Text,
    .StateTaxes = TxtStateTaxes.Text,
   .PaymentDueDate = DtpPaymentDueDate.Value,
  .AmountDue = TxtAmountDue.Text,
 .LatePaymentDueDate = DtpLatePaymentDueDate.Value,
.LateAmountDue = TxtLateAmountDue.Text
            }

        WaterBills.Add(Bill)

        Dim Options As JsonSerializerOptions = New JsonSerializerOptions()
        Options.WriteIndented = True

        Dim JsWaterBills = JsonSerializer.Serialize(WaterBills, GetType(List(Of WaterBill)), Options)
        File.WriteAllText(FiWaterBills.FullName, JsWaterBills)

        Close()
    End Sub

    Private sub BtnClose_Click(sender As Object, e As EventArgs) handles btnclose.click
            Close()
        end sub
End Class
  7. In the Solution Explorer, below the WaterBills folder, double-click Central.vb
  8. From the Toolbox, add a button to the form below the list view
  9. Change the characteristics of the button as follows:

    Stellar Water Point - Water Meters

    Control (Name) Other Properties
    ListView List View LvwWaterBills No Change
    Button Button BtnProcessWaterBill &Process Water Bill...
  10. On the Central form, double-click the Process Water Bill button
  11. Implement the event as follows: 
    Private Sub BtnProcessWaterBill_Click(sender As Object, e As EventArgs) Handles BtnProcessWaterBill.Click
    Dim Create As WaterBillsCreate = New WaterBillsCreate

    Create.ShowDialog()

    ShowWaterBills()
End Sub
  12. To execute the application, on the main menu, click Debug -> Start Without Debugging:

    Stellar Water Point

  13. On the Water Distribution form, click the Water Bills button:

    Stellar Water Point - Water Bills

  14. On the Water Bills form, click the Create Water Bill button:

    Stellar Water Point - Create Water Bill

  15. Enter the following values in the indicated text boxes or select the date values. Then click Find Customer Account, followed by Evaluate Water Bill, followed by Save Water Bill:

    Stellar Water Point - Create Water Bill

    Stellar Water Point - Create Water Bill

    Water Bill # Account # Reading Start Date Reading End Date Counter Reading Start Counter Reading End
    451474 2068-258-9486 01/11/2010 04/12/2010 103943 103956
    923633 5293-957-3395 01/17/2010 08/18/2010 256945 256972
    917829 9279-570-8394 02/15/2010 05/14/2010 5205 5222
    202666 6986-829-3741 03/08/2010 06/06/2010 5679 5690

    Stellar Water Point - Water Bills

  16. Close the forms and return to your programming environment

Water Bill Details

Sometimes, an employee just wants to view the information that is related to a water bill. We will create a form to make it possible.

Practical LearningPractical Learning: Showing a Water Bill

  1. To create a form, in the Solution Explorer, right-click StellarWaterPoint2 -> Add -> Form (Windows Forms)...
  2. For the Name of the form, type WaterBillsDetails
  3. Press Enter
  4. Design the form as follows:

    Stellar Water Point - New Water Bill

    Control Text Name Enabled
    Label Label &Water Bill #:    
    TextBox Text Box   TxtBillNumber  
    Button Button &Find Water Bill BtnFindWaterBill  
    GroupBox Group Box Customer Information    
    Label Label &Account #:    
    TextBox Text Box   TxtAccountNumber False
    Label Label Account Name:    
    TextBox Text Box   TxtAccountName False
    Label Label Account Type:    
    TextBox Text Box   TxtAccountType  
    Label Label Address:   False
    TextBox Text Box   TxtAddress False
    TextBox Text Box   TxtCity  
    TextBox Text Box   TxtCounty False
    TextBox Text Box   TxtState False
    TextBox Text Box   TxtZIPCode False
    Label Label _______________________________    
    Label Label Meter Details:    
    TextBox Text Box   TxtMeterDetails False
    GroupBox Group Box Meter Reading    
    Label Label Meter &Reading Start Date:    
    Text Box Text Box   TxtMeterReadingStartDate False
    Label Label Meter Reading &End Date:    
    Text Box Text Box   TxtMeterReadingEndDate False
    Label Label Coun&ter Reading Start:    
    TextBox Text Box   TxtCounterReadingStart False
    Label Label Counter Readi&ng End:    
    TextBox Text Box   TxtCounterReadingEnd False
    GroupBox Group Box Meter Result    
    Label Label Billing Days:    
    TextBox Text Box   TxtBillingDays False
    Label Label Total HCF:    
    TextBox Text Box   TxtTotalHCF False
    Label Label Total Gallons:    
    TextBox Text Box   TxtTotalGallons False
    Label Label First Tier Consumption:    
    TextBox Text Box   TxtFirstTierConsumption False
    Label Label Second Tier:    
    TextBox Text Box   TxtSecondTierConsumption False
    Label Label Last Tier:    
    TextBox Text Box   TxtLastTierConsumption False
    GroupBox Group Box Consumption Charges    
    Label Label Water Charges:    
    TextBox Text Box   TxtWaterCharges False
    Label Label Sewer Charges:    
    TextBox Text Box   TxtSewerCharges False
    Label Label Environment Charges:    
    TextBox Text Box   TxtEnvironmentCharges False
    Label Label Service Charges:    
    TextBox Text Box   TxtServiceCharges False
    Label Label Total Charges:    
    TextBox Text Box   TxtTotalCharges False
    GroupBox Group Box Taxes    
    Label Label Local Taxes:    
    TextBox Text Box   TxtLocalTaxes False
    Label Label State Taxes:    
    TextBox Text Box   TxtStateTaxes False
    GroupBox Group Box Water Bill Payment    
    Label Label Payment Due Date:    
    Date Time Picker Text Box   dtpPaymentDueDate False
    Label Label Amount Due:    
    TextBox Text Box   TxtAmountDue False
    Label Label Late Payment Due Date:    
    Text Box Text Box   TxtLatePaymentDueDate False
    Label Label &Late Amount Due:    
    TextBox Text Box   TxtLateAmountDue  
    Label Label Water Bill Id:    
    TextBox Text Box   TxtWaterBillId False
    Button Button &Close BtnClose  

    Form Properties

    Form Property Value
    FormBorderStyle FixedDialog
    Text Stellar Water Point - Water Bill Details
    StartPosition CenterScreen
    MaximizeBox False
    MinimizeBox False
  5. Right-click anywhere on the form and click View Code
  6. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class WaterBillsDetails
    Private Sub BtnFindWaterBill_Click(sender As Object, e As EventArgs) Handles BtnFindWaterBill.Click
        If String.IsNullOrEmpty(TxtWaterBillNumber.Text) Then
            MsgBox("You must provide a water bill number and then click the Find Water Bill button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            REM If the user didn't type a bill number but clicked Find Water Bill, don't do anything
            Exit Sub
        End If

        Dim StrWaterBills As String = Nothing
        Dim WaterBills As List(Of WaterBill) = New List(Of WaterBill)
        Dim FileWaterBills As String = "C:\Stellar Water Point16\WaterBills.json"

        Dim FiWaterBills As FileInfo = New FileInfo(FileWaterBills)

        Dim StrAccountsTypes As String = Nothing
        Dim AccountsTypes = New List(Of AccountType)
        Dim FileAccountsTypes As String = "C:\Stellar Water Point16\AccountsTypes.json"

        Dim FiAccountsTypes As FileInfo = New FileInfo(FileAccountsTypes)

        If fiWaterBills.Exists = True Then
            Using TrWaterBills As TextReader = New StreamReader(fiWaterBills.FullName)
                StrWaterBills = File.ReadAllText(FiWaterBills.FullName)
                WaterBills = JsonSerializer.Deserialize(StrWaterBills, GetType(List(Of WaterBill)))

                Dim Selected As IEnumerable(Of WaterBill) = WaterBills.Where(Function(Invoice) Invoice.BillNumber = TxtWaterBillNumber.Text)

                For Each Bill In Selected
                    TxtWaterBillId.Text = Bill.WaterBillId
                    TxtAccountNumber.Text = Bill.AccountNumber
                    TxtMeterReadingStartDate.Text = FormatDateTime(Bill.MeterReadingStartDate, DateFormat.LongDate)
                    TxtMeterReadingEndDate.Text = FormatDateTime(Bill.MeterReadingEndDate, DateFormat.LongDate)
                    TxtBillingDays.Text = Bill.BillingDays
                    TxtCounterReadingStart.Text = Bill.CounterReadingStart
                    TxtCounterReadingEnd.Text = Bill.CounterReadingEnd
                    TxtTotalHCF.Text = Bill.TotalHCF
                    TxtTotalGallons.Text = Bill.TotalGallons
                    TxtFirstTierConsumption.Text = FormatNumber(Bill.FirstTierConsumption)
                    TxtSecondTierConsumption.Text = FormatNumber(Bill.SecondTierConsumption)
                    TxtLastTierConsumption.Text = FormatNumber(Bill.LastTierConsumption)
                    TxtWaterCharges.Text = FormatNumber(Bill.WaterCharges)
                    TxtSewerCharges.Text = FormatNumber(Bill.SewerCharges)
                    TxtEnvironmentCharges.Text = FormatNumber(Bill.EnvironmentCharges)
                    TxtServiceCharges.Text = FormatNumber(Bill.ServiceCharges)
                    TxtTotalCharges.Text = FormatNumber(Bill.TotalCharges)
                    TxtLocalTaxes.Text = FormatNumber(Bill.LocalTaxes)
                    TxtStateTaxes.Text = FormatNumber(Bill.StateTaxes)
                    TxtPaymentDueDate.Text = FormatDateTime(Bill.PaymentDueDate, DateFormat.LongDate)
                    TxtAmountDue.Text = FormatNumber(Bill.AmountDue)
                    TxtLatePaymentDueDate.Text = FormatDateTime(Bill.LatePaymentDueDate, DateFormat.LongDate)
                    TxtLateAmountDue.Text = FormatNumber(Bill.LateAmountDue)
                Next
            End Using
        End If

        Dim StrCustomers = Nothing
        Dim Clients As List(Of Customer) = New List(Of Customer)
        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)

        Dim StrMeterNumber = Nothing

        If FiCustomers.Exists = True Then
            Using TrCustomers As TextReader = New StreamReader(FiCustomers.FullName)
                StrCustomers = File.ReadAllText(FiCustomers.FullName)
                Clients = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))

                Dim Customers As IEnumerable(Of Customer) = From Consumer
                                                            In Clients
                                                            Where Consumer.AccountNumber = TxtAccountNumber.Text
                                                            Select Consumer

                For Each Client As Customer In Customers
                    TxtAccountName.Text = Client.AccountName
                    StrMeterNumber = Client.MeterNumber

                    Dim TrAccountsTypess As TextReader = New StreamReader(FiAccountsTypes.FullName)
                    StrAccountsTypes = File.ReadAllText(FiAccountsTypes.FullName)
                    AccountsTypes = JsonSerializer.Deserialize(StrAccountsTypes, GetType(List(Of AccountType)))

                    For Each ActType As AccountType In AccountsTypes
                        If Client.AccountType = ActType.TypeCode Then
                            TxtAccountType.Text = String.Concat(ActType.TypeCode, " - ", ActType.TypeDecription)
                        End If
                    Next

                    TxtAddress.Text = Client.Address
                    TxtCity.Text = Client.City
                    TxtCounty.Text = Client.County
                    TxtState.Text = Client.State
                    TxtZIPCode.Text = Client.ZIPCode
                Next
            End Using
        End If

        If Len(StrMeterNumber) > 0 Then
            Dim StrWaterMeters As String = Nothing
            Dim WaterMeters As List(Of WaterMeter) = New List(Of WaterMeter)
            Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

            Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

            If FiWaterMeters.Exists = True Then
                StrWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
                WaterMeters = JsonSerializer.Deserialize(StrWaterMeters, GetType(List(Of WaterMeter)))

                Dim Meters As IEnumerable(Of WaterMeter) = From Measure
                                                           In WaterMeters
                                                           Where Measure.MeterNumber = StrMeterNumber
                                                           Select Measure

                For Each Meter As WaterMeter In Meters
                    TxtMeterDetails.Text = Meter.WaterMeterId & " - " &
                                           Meter.MeterNumber & " - " &
                                           Meter.Make & " " &
                                           Meter.Model &
                                           " (Meter Size: " & Meter.MeterSize & ")"
                Next
            End If
        End If
    End Sub

    Private Sub BtnClose_Click(sender As Object, e As EventArgs) Handles BtnClose.Click
        Close()
    End Sub
End Class
  7. In the Solution Explorer, below the WaterBills folder, double-click Central.vb to open its form
  8. From the Toolbox, add a button to the form below the list view and to the right of the New Water Bill button
  9. Change the characteristics of the button as follows:

    Stellar Water Point - Water Meters

    Control (Name) Other Properties
    ListView List View LvwWaterBills No Change
    Button Button No Change No Change
    Button Button BtnWaterBillDetails Water Bill &Details...
  10. Double-click the Water Bill &Details button
  11. Change the document as follows: 
    Private Sub BtnWaterBillsDetails(ByVal sender As Object, e As EventArgs) Handles BtnWaterBillDetails.Click
    Dim Details As WaterBillsDetails = New WaterBillsDetails

    Details.ShowDialog()

    ShowWaterBills()
End Sub
  12. To execute the application, on the main menu, click Debug -> Start Without Debugging

    Stellar Water Point

  13. On the Water Distribution form, click the Water Bills button:

    Stellar Water Point - Customers

  14. On the Water Bills form, click the View Water Bill button:

    Stellar Water Point - View Water Bill

  15. In the Water Bill # text box, type 917829
  16. Click the Find Water Bill button:

    Stellar Water Point - View Water Bill

  17. Close the forms and return to your programming environment

Water Bill Edition

If some aspect of a water bill changes, we will create a form that an employee can use to update the record.

Practical LearningPractical Learning: Creating a Water Bill Editor

  1. In the Solution Explorer, right-click StellarWaterPoint2 -> Add -> Form (Windows Forms...)
  2. Set the name of the form to WaterBillsEditor
  3. Click Add
  4. Using the Properties window, change the size of the new form to match the size of the WaterBillsCreate form
  5. Select everything in the Process Water Bill form and copy it
  6. Paste it in Water Bill Editor form
  7. Change the design of the Water Bill Editor form as follows (you will add only the controls that are not found in the New Water Bill form):

    Stellar Water Point - Water Bill Editor

    Control (Name) Text
    Button Button BtnFindWaterBill &Find Water Bill
    Button Button BtnUpdateWaterBill &Update Water Bill
  8. Right-click any section of the form and click View Code
  9. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class WaterBillsEditor
    Private Sub BtnFindWaterBill_Click(sender As Object, e As EventArgs) Handles BtnFindWaterBill.Click
        If String.IsNullOrEmpty(TxtWaterBillNumber.Text) Then
            MsgBox("You must provide a water bill number and then click the Find Water Bill button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            REM If the user didn't type a bill number but clicked Find Water Bill, don't do anything
            Exit Sub
        End If

        Dim StrWaterBills = Nothing
        Dim WaterBills As List(Of WaterBill) = New List(Of WaterBill)
        Dim FileWaterBills As String = "C:\Stellar Water Point16\WaterBills.json"

        Dim FiWaterBills As FileInfo = New FileInfo(FileWaterBills)

        Dim StrAccountsTypes As String = Nothing
        Dim AccountsTypes = New List(Of AccountType)
        Dim FileAccountsTypes = "C:\Stellar Water Point16\AccountsTypes.json"

        Dim FiAccountsTypes As FileInfo = New FileInfo(FileAccountsTypes)

        If FiWaterBills.Exists = True Then
            Using TrWaterBills As TextReader = New StreamReader(FiWaterBills.FullName)
                StrWaterBills = File.ReadAllText(FiWaterBills.FullName)
                WaterBills = JsonSerializer.Deserialize(StrWaterBills, GetType(List(Of WaterBill)))

                Dim Selected As IEnumerable(Of WaterBill) = WaterBills.Where(Function(Bill) Bill.BillNumber = TxtWaterBillNumber.Text)

                For Each Bill In Selected
                    TxtWaterBillId.Text = Bill.WaterBillId
                    MtbAccountNumber.Text = Bill.AccountNumber
                    DtpMeterReadingStartDate.Value = Bill.MeterReadingStartDate
                    DtpMeterReadingEndDate.Value = Bill.MeterReadingEndDate
                    TxtBillingDays.Text = Bill.BillingDays
                    TxtCounterReadingStart.Text = Bill.CounterReadingStart
                    TxtCounterReadingEnd.Text = Bill.CounterReadingEnd
                    TxtTotalHCF.Text = Bill.TotalHCF
                    TxtTotalGallons.Text = Bill.TotalGallons
                    TxtFirstTierConsumption.Text = FormatNumber(Bill.FirstTierConsumption)
                    TxtSecondTierConsumption.Text = FormatNumber(Bill.SecondTierConsumption)
                    TxtLastTierConsumption.Text = FormatNumber(Bill.LastTierConsumption)
                    TxtWaterCharges.Text = FormatNumber(Bill.WaterCharges)
                    TxtSewerCharges.Text = FormatNumber(Bill.SewerCharges)
                    TxtEnvironmentCharges.Text = FormatNumber(Bill.EnvironmentCharges)
                    TxtServiceCharges.Text = FormatNumber(Bill.ServiceCharges)
                    TxtTotalCharges.Text = FormatNumber(Bill.TotalCharges)
                    TxtLocalTaxes.Text = FormatNumber(Bill.LocalTaxes)
                    TxtStateTaxes.Text = FormatNumber(Bill.StateTaxes)
                    DtpPaymentDueDate.Value = Bill.PaymentDueDate
                    TxtAmountDue.Text = FormatNumber(Bill.AmountDue)
                    DtpLatePaymentDueDate.Value = Bill.LatePaymentDueDate
                    TxtLateAmountDue.Text = FormatNumber(Bill.LateAmountDue)
                Next
            End Using
        End If

        Dim StrCustomers = Nothing
        Dim Clients As List(Of Customer) = New List(Of Customer)
        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)

        Dim StrMeterNumber = Nothing

        If FiCustomers.Exists = True Then
            Using TrCustomers As TextReader = New StreamReader(FiCustomers.FullName)

                StrCustomers = File.ReadAllText(FiCustomers.FullName)
                Clients = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))

                Dim Customers As IEnumerable(Of Customer) = From Consumer
                                                            In Clients
                                                            Where Consumer.AccountNumber = MtbAccountNumber.Text
                                                            Select Consumer

                For Each Client As Customer In Customers
                    TxtAccountName.Text = Client.AccountName
                    StrMeterNumber = Client.MeterNumber

                    Dim TrAccountsTypess As TextReader = New StreamReader(FiAccountsTypes.FullName)
                    StrAccountsTypes = File.ReadAllText(FiAccountsTypes.FullName)
                    AccountsTypes = JsonSerializer.Deserialize(StrAccountsTypes, GetType(List(Of AccountType)))

                    For Each ActType As AccountType In AccountsTypes
                        If Client.AccountType = ActType.TypeCode Then
                            TxtAccountType.Text = String.Concat(ActType.TypeCode, " - ", ActType.TypeDecription)
                        End If
                    Next

                    TxtAddress.Text = Client.Address
                    TxtCity.Text = Client.City
                    TxtCounty.Text = Client.County
                    TxtState.Text = Client.State
                    TxtZIPCode.Text = Client.ZIPCode
                Next
            End Using
        End If

        Dim StrWaterMeters As String = Nothing
        Dim WaterMeters As List(Of WaterMeter) = New List(Of WaterMeter)
        Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

        Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

        If FiWaterMeters.Exists = True Then
            StrWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
            WaterMeters = JsonSerializer.Deserialize(StrWaterMeters, GetType(List(Of WaterMeter)))

            Dim Meters As IEnumerable(Of WaterMeter) = From Measure
                                                       In WaterMeters
                                                       Where Measure.MeterNumber = StrMeterNumber
                                                       Select Measure

            For Each Meter As WaterMeter In Meters
                TxtMeterDetails.Text = Meter.WaterMeterId & " - " &
                                       Meter.Make & " " &
                                       Meter.Model &
                                       " (Meter Size: " & Meter.MeterSize & ")"
            Next
        End If
    End Sub

    Private Sub BtnFindCustomerAccount_Click(sender As Object, e As EventArgs) Handles BtnFindCustomerAccount.Click
        If String.IsNullOrEmpty(MtbAccountNumber.Text) Then
            MsgBox("You must type a valid account number of a customer, " &
                   "and then click the Find Customer Account button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrCustomers = Nothing
        Dim StrAccountsTypes = Nothing
        Dim AccountsTypes = New List(Of AccountType)
        Dim Clients As List(Of Customer) = New List(Of Customer)
        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"
        Dim FileAccountsTypes = "C:\Stellar Water Point16\AccountsTypes.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)
        Dim FiAccountsTypes As FileInfo = New FileInfo(FileAccountsTypes)

        Dim StrMeterNumber = "Nothing"

        If FiCustomers.Exists = True Then
            Using TrCustomers As TextReader = New StreamReader(FiCustomers.FullName)
                StrCustomers = File.ReadAllText(FiCustomers.FullName)
                Clients = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))

                Dim customers As IEnumerable(Of Customer) = Clients.Where(Function(Client) Client.AccountNumber = MtbAccountNumber.Text)

                For Each Client As Customer In customers
                    TxtAccountName.Text = Client.AccountName
                    StrMeterNumber = Client.MeterNumber

                    Dim TrAccountsTypess As TextReader = New StreamReader(FiAccountsTypes.FullName)
                    StrAccountsTypes = File.ReadAllText(FiAccountsTypes.FullName)
                    AccountsTypes = JsonSerializer.Deserialize(StrAccountsTypes, GetType(List(Of AccountType)))

                    For Each ActType As AccountType In AccountsTypes
                        If Client.AccountType = ActType.TypeCode Then
                            TxtAccountType.Text = String.Concat(ActType.TypeCode, " - ", ActType.TypeDecription)
                        End If
                    Next

                    TxtAddress.Text = Client.Address
                    TxtCity.Text = Client.City
                    TxtCounty.Text = Client.County
                    TxtState.Text = Client.State
                    TxtZIPCode.Text = Client.ZIPCode
                Next
            End Using
        End If

        Dim StrWaterMeters As String = Nothing
        Dim WaterMeters As List(Of WaterMeter) = New List(Of WaterMeter)
        Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

        Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

        If Len(StrMeterNumber) > 0 Then

            If FiWaterMeters.Exists = True Then
                StrWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
                WaterMeters = JsonSerializer.Deserialize(StrWaterMeters, GetType(List(Of WaterMeter)))

                Dim Meters As IEnumerable(Of WaterMeter) = WaterMeters.Where(Function(Mtr) Mtr.MeterNumber = StrMeterNumber)

                For Each Meter As WaterMeter In Meters
                    TxtMeterDetails.Text = Meter.WaterMeterId & " - " &
                                           Meter.Make & " " &
                                           Meter.Model &
                                           " (Meter Size: " & Meter.MeterSize & ")"
                Next
            End If
        End If
    End Sub

    Private Sub DtpMeterReadingEndDate_ValueChanged(sender As Object, e As EventArgs) Handles DtpMeterReadingEndDate.ValueChanged
        TxtBillingDays.Text = DateDiff(DateInterval.Day, DtpMeterReadingStartDate.Value, DtpMeterReadingEndDate.Value) + 1
    End Sub

    Private Sub BtnEvaluateWaterBill_Click(sender As Object, e As EventArgs) Handles BtnEvaluateWaterBill.Click
        Dim CounterStart As Double = 0, CounterEnd = 0

        Try
            CounterStart = CDbl(TxtCounterReadingStart.Text)
        Catch FeCRStart As FormatException
            MsgBox("You must enter a valid value in the Counter Reading Start text box. " &
                   "The error produced is: " & FeCRStart.Message,
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
        End Try

        Try
            CounterEnd = CDbl(TxtCounterReadingEnd.Text)
        Catch FeCREnd As FormatException
            MsgBox("You must enter a valid value in the Counter Reading End text box. " &
                   "The error produced is: " & FeCREnd.Message,
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
        End Try

        Dim Consumption As Double = CounterEnd - CounterStart
        Dim Gallons As Double = Consumption * 748.05
        Dim StrAccountType As String = TxtAccountType.Text.Substring(1, 3)

        Dim Tiers As (first As Double, second As Double, last As Double) = WaterBillManager.CalculateTiers(StrAccountType, Gallons)

        Dim WaterCharges = Tiers.first + Tiers.second + Tiers.last
        Dim SewerCharges = WaterBillManager.CalculateSewerCharges(StrAccountType, WaterCharges)
        Dim EnvCharges = WaterBillManager.CalculateEnvironmentCharges(StrAccountType, WaterCharges)
        Dim SrvCharges = WaterBillManager.CalculateServiceCharges(StrAccountType, WaterCharges)
        Dim TotalCharges = WaterCharges + SewerCharges + EnvCharges + SrvCharges
        Dim LocalTaxes = WaterBillManager.CalculateLocalTaxes(StrAccountType, WaterCharges)
        Dim StateTaxes = WaterBillManager.CalculateStateTaxes(StrAccountType, WaterCharges)
        Dim AmtDue = TotalCharges + LocalTaxes + StateTaxes

        TxtTotalHCF.Text = Consumption
        TxtTotalGallons.Text = Math.Ceiling(Gallons)
        TxtFirstTierConsumption.Text = FormatNumber(Tiers.first, 2)
        TxtSecondTierConsumption.Text = FormatNumber(Tiers.second)
        TxtLastTierConsumption.Text = FormatNumber(Tiers.last)
        TxtWaterCharges.Text = FormatNumber(WaterCharges)
        TxtSewerCharges.Text = FormatNumber(SewerCharges)
        TxtEnvironmentCharges.Text = FormatNumber(EnvCharges)
        TxtServiceCharges.Text = FormatNumber(SrvCharges)
        TxtTotalCharges.Text = FormatNumber(TotalCharges)
        TxtLocalTaxes.Text = FormatNumber(LocalTaxes)
        TxtStateTaxes.Text = FormatNumber(StateTaxes)
        DtpPaymentDueDate.Value = WaterBillManager.SetPaymentDueDate(StrAccountType, DtpMeterReadingEndDate.Value)
        TxtAmountDue.Text = FormatNumber(AmtDue)
        DtpLatePaymentDueDate.Value = WaterBillManager.SetLatePaymentDueDate(StrAccountType, DtpMeterReadingEndDate.Value)
        TxtLateAmountDue.Text = FormatNumber(WaterBillManager.CalculateLateAmountDue(StrAccountType, AmtDue))
    End Sub

    Private Sub BtnUpdateWaterBill_Click(sender As Object, e As EventArgs) Handles BtnUpdateWaterBill.Click
        If IsNothing(TxtWaterBillNumber.Text) Then
            MsgBox("You must provide the bill number of the " &
                        "water bill you are trying to update.")
            Exit Sub
        End If

        If IsNothing(MtbAccountNumber.Text) Then
            MsgBox("Please make sure you provide the account number of the customer " &
                            "associated with the water bill you are trying to update.")
            Exit Sub
        End If

        Dim StrWaterBills As String = Nothing
        Dim WaterBills As List(Of WaterBill) = New List(Of WaterBill)
        Dim FileWaterBills As String = "C:\Stellar Water Point16\WaterBills.json"

        Dim FiWaterBills As FileInfo = New FileInfo(FileWaterBills)

        If FiWaterBills.Exists = True Then
            StrWaterBills = File.ReadAllText(FiWaterBills.FullName)
            WaterBills = JsonSerializer.Deserialize(StrWaterBills, GetType(List(Of WaterBill)))

            Dim Bill As WaterBill = WaterBills.Find(Function(invoice) invoice.BillNumber = TxtWaterBillNumber.Text)

            If Not Bill Is Nothing Then
                Bill.WaterBillId = TxtWaterBillId.Text
                Bill.BillNumber = TxtWaterBillNumber.Text
                Bill.AccountNumber = MtbAccountNumber.Text
                Bill.MeterReadingStartDate = DtpMeterReadingStartDate.Value
                Bill.MeterReadingEndDate = DtpMeterReadingEndDate.Value
                Bill.BillingDays = TxtBillingDays.Text
                Bill.CounterReadingStart = TxtCounterReadingStart.Text
                Bill.CounterReadingEnd = TxtCounterReadingEnd.Text
                Bill.TotalHCF = TxtTotalHCF.Text
                Bill.TotalGallons = TxtTotalGallons.Text
                Bill.FirstTierConsumption = TxtFirstTierConsumption.Text
                Bill.SecondTierConsumption = TxtSecondTierConsumption.Text
                Bill.LastTierConsumption = TxtLastTierConsumption.Text
                Bill.WaterCharges = TxtWaterCharges.Text
                Bill.SewerCharges = TxtSewerCharges.Text
                Bill.EnvironmentCharges = TxtEnvironmentCharges.Text
                Bill.ServiceCharges = TxtServiceCharges.Text
                Bill.TotalCharges = TxtTotalCharges.Text
                Bill.LocalTaxes = TxtLocalTaxes.Text
                Bill.StateTaxes = TxtStateTaxes.Text
                Bill.PaymentDueDate = DtpPaymentDueDate.Value
                Bill.AmountDue = TxtAmountDue.Text
                Bill.LatePaymentDueDate = DtpLatePaymentDueDate.Value
                Bill.LateAmountDue = TxtLateAmountDue.Text

                Dim Options = New JsonSerializerOptions()
                Options.WriteIndented = True

                Dim JsWaterBills = JsonSerializer.Serialize(WaterBills, GetType(List(Of WaterBill)), Options)
                File.WriteAllText(FiWaterBills.FullName, JsWaterBills)
            End If
        End If

        Close()
    End Sub

    Private Sub BtnClose_Click(sender As Object, e As EventArgs) Handles BtnClose.Click
        Close()
    End Sub
End Class
  10. In the Solution Explorer, below the WaterBills folder, double-click Central.vb
  11. From the Toolbox, add a button to the form below the list view and on the right side of the View Water Bill button
  12. Change the characteristics of the button as follows:

    Stellar Water Point - Water Meters

    Control (Name) Text
    ListView List View LvwWaterBills  
    Button Button BtnNewWaterBill  
    Button Button BtnViewWaterBill  
    Button Button BtnEditWaterBill &Edit Water Bill...
  13. Double-click the Edit Water Bill button
  14. Implement the event as follows: 
    Private Sub BtnWaterBillsEditor(ByVal sender As Object, e As EventArgs) Handles BtnWaterBillEditor.Click
    Dim Editor As WaterBillsEditor = New WaterBillsEditor

    Editor.ShowDialog()

    ShowWaterBills()
End Sub
  15. To execute the application, on the main menu, click Debug -> Start Without Debugging

    Stellar Water Point

  16. On the main form of the application, click the Water Bills button:

    Stellar Water Point - Water Bills

  17. Click the Edit Water Bill button:

    Stellar Water Point - Water Bill Editor

  18. In the Water Bill # text, type 923633
  19. Click the Find Water Bill button

    Stellar Water Point - Water Bill Editor

  20. Change the following values: 
    Account #:                9249-379-6848 and click Find Customer Account
Meter Reading Start Date: 1/19/2010
Meter Reading End Date:   4/17/2010
Counter Reading Start:    256953
Counter Reading End:      256966
  21. Click the Evaluate Water Bill button:

    Stellar Water Point - Water Bill Editor

  22. Click the Update Water Bill button and click OK on the message box:

    Stellar Water Point - Water Bills

  23. Close the forms and return to your programming environment

Water Bill Deletion

If a water bill is useless and must not be kept as a record in the system, an employee must be able to delete it. We will create a form that makes it possible to delete a water bill.

Practical LearningPractical Learning: Deleting a Water Bill Record

  1. To create a form, in the Solution Explorer, right-click the WaterBills folder -> Add -> Form (Windows Forms...)
  2. Change the file Name to Delete
    3. Click Add Resize the form to have the same size as the Water Bill Details form
  3. Select and copy everything in the Water Bill Details form
  4. Paste it in the new Water Bill Delete form
  5. Change the design of the form as follows (you will add only one button):

    Stellar Water Point - Water Bill Deletion

    Control (Name) Text
    Button Button BtnDeleteWaterBill &Delete Water Bill
  6. On the form, double-click the Find Water Bill button
  7. Change the document as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class WaterBillsDelete
    Private Sub BtnFindWaterBill_Click(sender As Object, e As EventArgs) Handles BtnFindWaterBill.Click
        If String.IsNullOrEmpty(TxtWaterBillNumber.Text) Then
            MsgBox("You must provide a water bill number and then click the Find Water Bill button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            REM If the user didn't type a bill number but clicked Find Water Bill, don't do anything
            Exit Sub
        End If

        Dim StrWaterBills As String = Nothing
        Dim WaterBills As List(Of WaterBill) = New List(Of WaterBill)
        Dim FileWaterBills As String = "C:\Stellar Water Point16\WaterBills.json"

        Dim FiWaterBills As FileInfo = New FileInfo(FileWaterBills)

        Dim StrAccountsTypes As String = Nothing
        Dim AccountsTypes = New List(Of AccountType)
        Dim FileAccountsTypes As String = "C:\Stellar Water Point16\AccountsTypes.json"

        Dim FiAccountsTypes As FileInfo = New FileInfo(FileAccountsTypes)

        If FiWaterBills.Exists = True Then
            Using TrWaterBills As TextReader = New StreamReader(FiWaterBills.FullName)
                StrWaterBills = File.ReadAllText(FiWaterBills.FullName)
                WaterBills = JsonSerializer.Deserialize(StrWaterBills, GetType(List(Of WaterBill)))

                Dim Selected As IEnumerable(Of WaterBill) = WaterBills.Where(Function(Invoice) Invoice.BillNumber = TxtWaterBillNumber.Text)

                For Each Bill In Selected
                    TxtWaterBillId.Text = Bill.WaterBillId
                    TxtAccountNumber.Text = Bill.AccountNumber
                    TxtMeterReadingStartDate.Text = FormatDateTime(Bill.MeterReadingStartDate, DateFormat.LongDate)
                    TxtMeterReadingEndDate.Text = FormatDateTime(Bill.MeterReadingEndDate, DateFormat.LongDate)
                    TxtBillingDays.Text = Bill.BillingDays
                    TxtCounterReadingStart.Text = Bill.CounterReadingStart
                    TxtCounterReadingEnd.Text = Bill.CounterReadingEnd
                    TxtTotalHCF.Text = Bill.TotalHCF
                    TxtTotalGallons.Text = Bill.TotalGallons
                    TxtFirstTierConsumption.Text = FormatNumber(Bill.FirstTierConsumption)
                    TxtSecondTierConsumption.Text = FormatNumber(Bill.SecondTierConsumption)
                    TxtLastTierConsumption.Text = FormatNumber(Bill.LastTierConsumption)
                    TxtWaterCharges.Text = FormatNumber(Bill.WaterCharges)
                    TxtSewerCharges.Text = FormatNumber(Bill.SewerCharges)
                    TxtEnvironmentCharges.Text = FormatNumber(Bill.EnvironmentCharges)
                    TxtServiceCharges.Text = FormatNumber(Bill.ServiceCharges)
                    TxtTotalCharges.Text = FormatNumber(Bill.TotalCharges)
                    TxtLocalTaxes.Text = FormatNumber(Bill.LocalTaxes)
                    TxtStateTaxes.Text = FormatNumber(Bill.StateTaxes)
                    TxtPaymentDueDate.Text = FormatDateTime(Bill.PaymentDueDate, DateFormat.LongDate)
                    TxtAmountDue.Text = FormatNumber(Bill.AmountDue)
                    TxtLatePaymentDueDate.Text = FormatDateTime(Bill.LatePaymentDueDate, DateFormat.LongDate)
                    TxtLateAmountDue.Text = FormatNumber(Bill.LateAmountDue)
                Next
            End Using
        End If

        Dim StrCustomers = Nothing
        Dim Clients As List(Of Customer) = New List(Of Customer)
        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)

        Dim StrMeterNumber = Nothing

        If FiCustomers.Exists = True Then
            Using TrCustomers As TextReader = New StreamReader(FiCustomers.FullName)
                StrCustomers = File.ReadAllText(FiCustomers.FullName)
                Clients = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))

                Dim Customers As IEnumerable(Of Customer) = From Consumer
                                                            In Clients
                                                            Where Consumer.AccountNumber = TxtAccountNumber.Text
                                                            Select Consumer

                For Each Client As Customer In Customers
                    TxtAccountName.Text = Client.AccountName
                    StrMeterNumber = Client.MeterNumber

                    Dim TrAccountsTypess As TextReader = New StreamReader(FiAccountsTypes.FullName)
                    StrAccountsTypes = File.ReadAllText(FiAccountsTypes.FullName)
                    AccountsTypes = JsonSerializer.Deserialize(StrAccountsTypes, GetType(List(Of AccountType)))

                    For Each ActType As AccountType In AccountsTypes
                        If Client.AccountType = ActType.TypeCode Then
                            TxtAccountType.Text = String.Concat(ActType.TypeCode, " - ", ActType.TypeDecription)
                        End If
                    Next

                    TxtAddress.Text = Client.Address
                    TxtCity.Text = Client.City
                    TxtCounty.Text = Client.County
                    TxtState.Text = Client.State
                    TxtZIPCode.Text = Client.ZIPCode
                Next
            End Using
        End If

        If Len(StrMeterNumber) > 0 Then
            Dim StrWaterMeters As String = Nothing
            Dim WaterMeters As List(Of WaterMeter) = New List(Of WaterMeter)
            Dim FileWaterMeters = "C:\Stellar Water Point16\WaterMeters.json"

            Dim FiWaterMeters As FileInfo = New FileInfo(FileWaterMeters)

            If FiWaterMeters.Exists = True Then
                StrWaterMeters = File.ReadAllText(FiWaterMeters.FullName)
                WaterMeters = JsonSerializer.Deserialize(StrWaterMeters, GetType(List(Of WaterMeter)))

                Dim Meters As IEnumerable(Of WaterMeter) = From Measure
                                                           In WaterMeters
                                                           Where Measure.MeterNumber = StrMeterNumber
                                                           Select Measure

                For Each Meter As WaterMeter In Meters
                    TxtMeterDetails.Text = Meter.WaterMeterId & " - " &
                                           Meter.MeterNumber & " - " &
                                           Meter.Make & " " &
                                           Meter.Model &
                                           " (Meter Size: " & Meter.MeterSize & ")"
                Next
            End If
        End If
    End Sub

    Private Sub BtnDeleteWaterBill_Click(sender As Object, e As EventArgs) Handles BtnDeleteWaterBill.Click
        If String.IsNullOrEmpty(TxtWaterBillNumber.Text) Then
            MsgBox("Please provide the bill number of the water bill you want to delete, " &
                   "and then click the Find Water Bill button.",
                   MsgBoxStyle.OkOnly, "Stellar Water Point")
            Exit Sub
        End If

        Dim StrWaterBills As String = Nothing
        Dim WaterBills As List(Of WaterBill) = New List(Of WaterBill)
        Dim FileWaterBills As String = "C:\Stellar Water Point16\WaterBills.json"

        Dim FiWaterBills As FileInfo = New FileInfo(FileWaterBills)

        If FiWaterBills.Exists = True Then
            StrWaterBills = File.ReadAllText(FiWaterBills.FullName)
            WaterBills = JsonSerializer.Deserialize(StrWaterBills, GetType(List(Of WaterBill)))

            Dim Bill As WaterBill = WaterBills.Find(Function(invoice) invoice.BillNumber = TxtWaterBillNumber.Text)

            Dim Answer As MsgBoxResult = MsgBox("Are you sure you want to delete (or remove) or cancel " &
                                                "this water bill from the system (you cannot undo the action)?",
                                                MsgBoxStyle.YesNoCancel, "Stellar Water Point")
            If Bill IsNot Nothing Then
                REM If the user clicks Yes, save the updated water bill and close the form
                If Answer = MsgBoxResult.Yes Then
                    WaterBills.Remove(Bill)

                    Dim Options As JsonSerializerOptions = New JsonSerializerOptions()
                    Options.WriteIndented = True

                    Dim JsWaterBills As String = JsonSerializer.Serialize(WaterBills, GetType(List(Of WaterBill)), Options)
                    File.WriteAllText(FiWaterBills.FullName, JsWaterBills)

                    MsgBox("The water bill has been deleted (or removed, or cancelled) from our system.",
                           MsgBoxStyle.OkOnly, "Stellar Water Point")

                    Close()
                ElseIf Answer = MsgBoxResult.No Then
                    REM If the user clicks No, leave the form displaying
                    BtnFindWaterBill_Click(sender, e)
                Else
                    REM If the user clicks Cancel, close the Delete form
                    REM and return to the list of water bills
                    Close()
                End If
            End If
        End If
    End Sub

    Private Sub BtnClose_Click(sender As Object, e As EventArgs) Handles BtnClose.Click
        Close()
    End Sub
End Class
  8. In the Solution Explorer, below the WaterBills folder, double-click Central.vb to open its form
  9. From the Toolbox, add two buttons to the form below the list view and to the right of the Edit Water Bill button
  10. Change the form design as follows:

    Stellar Water Point - Water Bills

    Control (Name) Text Other Properties
    ListView List View LvwWaterBills   Anchor: Bottom, Top, Bottom, Left, Right
    Button Button BtnProcessWaterBill &Process Water Bill... Anchor: Bottom, Right
    Button Button BtnViewWaterBill &View Water Bill... Anchor: Bottom, Right
    Button Button BtnEditWaterBill &Edit Water Bill... Anchor: Bottom, Right
    Button Button BtnDeleteWaterBill &Delete Water Bill... Anchor: Bottom, Right
    Button Button BtnClose &Close Anchor: Bottom, Right
  11. Right-click any area of the form and click View Code
  12. Create two events as follows: 
    Imports System.IO
Imports System.Text.Json

Public Class WaterBillsCentral
    Private Sub ShowWaterBills()
        Dim StrCustomers = Nothing
        Dim StrWaterBills = Nothing
        Dim StrAccountsTypes = Nothing

        Dim AccountsTypes = New List(Of AccountType)
        Dim Clients As List(Of Customer) = New List(Of Customer)
        Dim WaterBills As List(Of WaterBill) = New List(Of WaterBill)

        Dim FileCustomers = "C:\Stellar Water Point16\Customers.json"
        Dim FileAccountsTypes = "C:\Stellar Water Point16\AccountsTypes.json"
        Dim FileWaterBills As String = "C:\Stellar Water Point16\WaterBills.json"

        Dim FiCustomers As FileInfo = New FileInfo(FileCustomers)
        Dim FiWaterBills As FileInfo = New FileInfo(FileWaterBills)
        Dim FiAccountsTypes As FileInfo = New FileInfo(FileAccountsTypes)

        If FiCustomers.Exists = True Then
            Using TrCustomers As TextReader = New StreamReader(FiCustomers.FullName)
                StrCustomers = File.ReadAllText(FiCustomers.FullName)

                Clients = JsonSerializer.Deserialize(StrCustomers, GetType(List(Of Customer)))
            End Using
        End If

        Dim TrAccountsTypess As TextReader = New StreamReader(FiAccountsTypes.FullName)
        StrAccountsTypes = File.ReadAllText(FiAccountsTypes.FullName)
        AccountsTypes = JsonSerializer.Deserialize(StrAccountsTypes, GetType(List(Of AccountType)))

        Dim StrAccountSummary As String

        If FiWaterBills.Exists = True Then
            Using TrWaterBills As TextReader = New StreamReader(FiWaterBills.FullName)
                StrWaterBills = File.ReadAllText(FiWaterBills.FullName)

                WaterBills = JsonSerializer.Deserialize(StrWaterBills, GetType(List(Of WaterBill)))

                LvwWaterBills.Items.Clear()

                For Each Invoice As WaterBill In WaterBills
                    Dim LviWaterBill As ListViewItem = New ListViewItem(Invoice.WaterBillId)

                    LviWaterBill.SubItems.Add(Invoice.BillNumber)

                    Dim Client As IEnumerable(Of Customer) = Clients.Where(Function(Cust) Cust.AccountNumber = Invoice.AccountNumber)

                    StrAccountSummary = Invoice.AccountNumber

                    For Each Cust In Clients
                        If Cust.AccountNumber = Invoice.AccountNumber Then

                            For Each ActType As AccountType In AccountsTypes
                                If Cust.AccountType = ActType.TypeCode Then
                                    StrAccountSummary = StrAccountSummary & " - " &
                                                        Cust.AccountName & ", Acnt Type: " & String.Concat(ActType.TypeCode, " - ", ActType.TypeDecription) &
                                                        ", (Mtr #: " & Cust.MeterNumber & ")"
                                End If
                            Next
                        End If
                    Next

                    For Each Cust As Customer In Clients
                        LviWaterBill.SubItems.Add(StrAccountSummary)

                        LviWaterBill.SubItems.Add(Invoice.MeterReadingStartDate.ToShortDateString())
                        LviWaterBill.SubItems.Add(Invoice.MeterReadingEndDate.ToShortDateString())
                        LviWaterBill.SubItems.Add(Invoice.BillingDays)
                        LviWaterBill.SubItems.Add(Invoice.CounterReadingStart)
                        LviWaterBill.SubItems.Add(Invoice.CounterReadingEnd)
                        LviWaterBill.SubItems.Add(Invoice.TotalHCF)
                        LviWaterBill.SubItems.Add(Invoice.TotalGallons)
                        LviWaterBill.SubItems.Add(Invoice.PaymentDueDate.ToShortDateString())
                        LviWaterBill.SubItems.Add(Invoice.AmountDue)
                    Next

                    LvwWaterBills.Items.Add(LviWaterBill)
                Next
            End Using
        End If
    End Sub

    Private Sub WaterBillsCentral_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ShowWaterBills()
    End Sub

    Private Sub BtnProcessWaterBill_Click(sender As Object, e As EventArgs) Handles BtnProcessWaterBill.Click
        Dim Create As WaterBillsCreate = New WaterBillsCreate

        Create.ShowDialog()

        ShowWaterBills()
    End Sub

    Private Sub BtnWaterBillsDetails(ByVal sender As Object, e As EventArgs) Handles BtnWaterBillDetails.Click
        Dim Details As WaterBillsDetails = New WaterBillsDetails

        Details.ShowDialog()

        ShowWaterBills()
    End Sub

    Private Sub BtnWaterBillsEditor(ByVal sender As Object, e As EventArgs) Handles BtnWaterBillEditor.Click
        Dim Editor As WaterBillsEditor = New WaterBillsEditor

        Editor.ShowDialog()

        ShowWaterBills()
    End Sub

    Private Sub BtnDeleteWaterBill_Click(sender As Object, e As EventArgs) Handles BtnDeleteWaterBill.Click
        Dim Delete As WaterBillsDelete = New WaterBillsDelete

        Delete.ShowDialog()

        ShowWaterBills()
    End Sub

    Private Sub BtnClose_Click(sender As Object, e As EventArgs) Handles BtnClose.Click
        Close()
    End Sub
End Class
  13. To execute, on the main menu, click Debug -> Start Without Debugging:

  14. On the Stellar Water Point form, click the Water Bills button

    Stellar Water Point - Water Bills

  15. On the Water Bills form, click the Delete Water Bill button

    Stellar Water Point - Water Bill Deletion

  16. In the Water Bill # text box, type 917829:

    Stellar Water Point - Water Bill Deletion

  17. Click Find Water Bill

    Stellar Water Point - Water Bill Deletion

  18. Click Delete Water Bill:

    Stellar Water Point - Water Bill Deletion

  19. Read the message in the message box and click Yes:

    Stellar Water Point - Water Bill Deletion

  20. Read the message in the message box and click OK:

    Stellar Water Point - Water Bills

  21. Close the forms and return to your programming environment
  22. Close Microsoft Visual Studio
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