Introduction

A text-based database is an application used to create, keep, and manage records. You have many options. One way to store the records of a database is as text. Even then, you still have many option. One solution is to create and manage records using a collection class.

Besides using a collection class to create and manage records, you also have to decide in what format you would keep the record. For this example, we will save the records in XML.

Practical Learning: Introducing MDI Applications

1. Start Microsoft Visual Studio
2. Create a Windows Forms App named StellarWaterPoint2
3. To create a form, on the main menu, click Project -> Add Form (Windows Forms)...
4. In the middle list, click About Box (Windows Forms)
5. Change the file Name to AboutSWP
6. Click Add
7. In the Solution Explorer, right-click StellarWaterPoint1 -> Add -> New Folder
8. Type Models as the name of the folder

Water Meters

A water meter is a mechanical device used to measure the amount of water that is consumed. To deal with it, we will create a class and forms.

Practical Learning: Starting Water Meters Issues

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 WaterMeter
4. Click Add
5. Change the code as follows:

   namespace StellarWaterPoint2.Models
   {
       internal readonly record struct WaterMeter
       {
           public readonly string? MeterNumber { get; init; }
           public readonly string? Make        { get; init; }
           public readonly string? Model       { get; init; }
           public readonly string? MeterSize   { get; init; }
       }
   }

6. In the Solution Explorer, right-click StellarWaterPoint1 -> Add -> New Folder
7. Type WaterMeters as the name of the folder
8. To create a form, in the Solution Explorer, right-click WaterMeters -> Add -> Form(Windows Forms)...
9. Type Create
10. Press Enter
11. Design the form as follows:

    

    Control		(Name)	Text	Other Properties
    Label			&Meter #:
    MaskedTextBox		mtbMeterNumber		Masked: 000-00-000
    Label			M&ake:
    TextBox		txtMake
    Label			M&odel:
    TextBox		txtModel		Modifiers: Public
    Label			Me&ter Size:
    TextBox		txtMeterSize
    Button		btnSaveWateMeter	S&ave Water Meter

12. To create a form, in the Solution Explorer, right-click WaterMeters -> Add -> Form(Windows Forms)...
13. Type Editor
14. Press Enter
15. Resize the Editor form to have the same size as the Create form
16. Copy everything from the Create form and paste it in the Editor form
17. Change the design as follows:

    

    Control		(Name)	Text
    Button		btnFindWateMeter	&Find Water Meter
    Button		btnUpdateWateMeter	&Update Water Meter

18. To create a form, in the Solution Explorer, right-click WaterMeters -> Add -> Form(Windows Forms)...
19. Type Delete
20. Press Enter
21. Resize the Editor form to have the same size as the Editor form
22. Copy everything from the Editor form and paste it in the Delete form
23. Change the bottom button as follows:

    

    Control		(Name)	Text
    Button		btnDeleteWateMeter	&Delete Water Meter

24. To create a form, in the Solution Explorer, right-click WaterMeters -> Add -> Form(Windows Forms)...
25. Type Manage
26. Press Enter
27. In the Toolbox, click the ListView button and click the form
28. On the form, right-click the list view and click Edit Columns...
29. Create the columns as follows:

    (Name)	Text	Width
    colWaterMeterId	Id	40
    colMeterNumber	Meter #	150
    colMake	Make	225
    colModel	Model	100
    colMeterSize	Meter Size	150

30. Click OK
31. Complete the design of the form as follows:

    

    Control		(Name)	Other Properties
    ListView		lvwWaterMeters	FullRowSelect: True GridLines: True View: Details Anchor: Top, Bottom, Left, Right

Customers

Customers are families or businesses that consume a product or service, which is the case for water consumption. To deal with these issues, we will create a class and forms.

Practical Learning: Preparing Customers Accounts

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:

   namespace StellarWaterPoint1.Models
   {
       internal readonly record struct Customer
       {
           public readonly string? AccountNumber { get; init; }
           public readonly string? MeterNumber   { get; init; }
           public readonly string? FirstName     { get; init; }
           public readonly string? LastName      { get; init; }
           public readonly string? Address       { get; init; }
           public readonly string? City          { get; init; }
           public readonly string? County        { get; init; }
           public readonly string? State         { get; init; }
           public readonly string? ZIPCode       { get; init; }
       }
   }

6. In the Solution Explorer, right-click StellarWaterPoint1 -> Add -> New Folder
7. Type Customers as the name of the folder
8. To create a form, on the main menu, click Customers -> Add Form (Windows Forms)...
9. Type Create as the name of the file
10. Click Add
11. Design the form as follows:

    

    Control		(Name)	Text	Mask
    Label			&Account #:
    MaskedTextBox		mtbAccountNumber		Masked: 0000-000-0000
    Label			&Meter #:
    MaskedTextBox		mtbMeterNumber		Masked: 000-00-000
    Button		btnFindWaterMeter	&Find Water Meter
    Label			Meter &Details:
    TextBox		txtMeterDetails
    Label			&First Name:
    TextBox		txtFirstName
    Label			&Last Name:
    TextBox		txtLastName
    Label			&Address:
    TextBox		txtAddress
    Label			C&ity:
    TextBox		txtCity
    Label			C&ounty:
    TextBox		txtCounty
    Label			&State:
    TextBox		txtState
    Label			&ZIP-Code:
    MaskedTextBox		mtbZIPCode		Masked: Zip-Code
    Button		btnSaveCustomerAccount	S&ave Customer Account

12. To create a form, in the Solution Explorer, right-click Customers -> Add -> Form (Windows Forms)...
13. Type Editor
14. Press Enter
15. Resize the Editor form to have the same size as the Create form
16. Copy everything from the Create form and paste it in the Editor form
17. Change the design as follows:

    

    Control		(Name)	Text
    Button		btnFindCustomer	&Find Customer
    Button		btnUpdateCustomerAccount	&Update Customer Account

18. To create a form, in the Solution Explorer, right-click Customers -> Add -> Form (Windows Forms)...
19. Type Delete
20. Press Enter
21. Resize the Editor form to have the same size as the Editor form
22. Copy everything from the Editor form and paste it in the Delete form
23. Delete the Find Water Meter button and change the bottom button as follows:

    

    Control		(Name)	Text
    Button		btnDeleteCustomerAccount	&Delete Customer Account

24. To create a form, in the Solution Explorer, right-click Models -> Add -> Form (Windows Forms)...
25. Type ViewAll
26. Press Enter
27. In the Toolbox, click the ListView button and click the form
28. On the form, right-click the list view and click Edit Columns...
29. Create the columns as follows:

    (Name)	Text	TextAlign	Width
    colCustomerId	Id		40
    colAccountNumber	Account #	Center	175
    colMeterNumber	Meter #	Center	150
    colFirstName	First Name		125
    colLastName	Last Name		125
    colAddress	Address		250
    colCity	City		125
    colCounty	County		150
    colState	State	Center
    colZIPCode	ZIP-Code	Center	125

30. Click OK
31. Complete the design of the form as follows:

    

    Control		(Name)	Text	Other Properties
    ListView		lvwCustomers		FullRowSelect: True GridLines: True View: Details Anchor: Top, Bottom, Left, Right

Water Bills

Bills are the natural results and benefits of services and products that people and businesses consume. To prepare them, we will create a class and forms.

Practical Learning: Preparing Bills

1. To create another class, in the Solution Explorer, right-click Models -> Add -> Class...
2. On the main menu, click Project -> Add Class...
3. Replace the name with WaterBill
4. Click Add
5. Change the code as follows:

   namespace StellarWaterPoint1.Models
   {
       internal readonly record struct WaterBill
       {
           public readonly int     BillNumber            { get; init; }
           public readonly string? AccountNumber         { get; init; }
           public readonly string? MeterReadingStartDate { get; init; }
           public readonly string? MeterReadingEndDate   { get; init; }
           public readonly int     BillingDays           { get; init; }
           public readonly double  CounterReadingStart   { get; init; }
           public readonly double  CounterReadingEnd     { get; init; }
           public readonly double  TotalGallons          { get; init; }
           public readonly double  TotalCCF              { get; init; }
           public readonly double  FirstTierConsumption  { get; init; }
           public readonly double  SecondTierConsumption { get; init; }
           public readonly double  LastTierConsumption   { get; init; }
           public readonly double  WaterCharges          { get; init; }
           public readonly double  SewerCharges          { get; init; }
           public readonly double  EnvironmentCharges    { get; init; }
           public readonly double  TotalCharges          { get; init; }
           public readonly double  LocalTaxes            { get; init; }
           public readonly double  StateTaxes            { get; init; }
           public readonly double  AmountDue             { get; init; }
           public readonly string? PaymentDueDate        { get; init; }
           public readonly double  LateAmountDue         { get; init; }
           public readonly string? LatePaymentDueDate    { get; init; }
       }
   }

6. In the Solution Explorer, right-click StellarWaterPoint1 -> Add -> New Folder
7. Type WaterBills as the name of the folder
8. To create a form, in the Solution Explorer, right-click WaterBills -> Add -> Form (Windows Forms)...
9. Type Create as the name of the file
10. Press Enter
11. Design the form as follows:

    

    Control		(Name)	Text	Other Properties
    Label			Water Bill #:
    TextBox		txtBillNumber
    GroupBox			Customer Information
    Label			Account #:
    MaskedTextBox		mtbAccountNumber		Masked: 0000-000-0000
    Button		btnFindCustomerAccount	Find Customer Account
    Label			Customer Name:
    TextBox		txtCustomerName
    Label			Address:
    TextBox		txtAddress
    TextBox		txtCity
    TextBox		txtCounty
    TextBox		txtState
    MaskedTextBox		mtbZIPCode		Masked: Zip-Code
    Label			_______________________
    Label			Meter Details:
    TextBox		txtMeterDetails	Modifiers: Public
    GroupBox			Meter Reading
    Label			Meter Reading Start Date:
    DateTimePicker		dtpMeterReadingStartDate
    Label			Meter Reading End Date:
    DateTimePicker		dtpMeterReadingEndDate
    Label			Counter Reading Start:
    TextBox		txtCounterReadingStart
    Label			Counter Reading End:
    TextBox		txtCounterReadingEnd
    Button		btnEvaluateWaterBill	Evaluate Water Bill
    GroupBox			Meter Result
    Label			Billing Days:
    TextBox		txtBillingDays		TextAlign: Right
    Label			Total Gallons:
    TextBox		txtTotalGallons		TextAlign: Right
    Label			Total CCF:
    TextBox		txtTotalCCF		TextAlign: Right
    Label			First Tier Consumption:
    TextBox		txtFirstTierConsumption		TextAlign: Right
    Label			Second Tier:
    TextBox		txtSecondTierConsumption		TextAlign: Right
    Label			Last Tier:
    TextBox		txtLastTierConsumption		TextAlign: Right
    GroupBox			Consumption Charges
    Label			Water Charges:
    TextBox		txtWaterCharges		TextAlign: Right
    Label			Sewer Charges:
    TextBox		txtSewerCharges		TextAlign: Right
    Label			Environment Charges:
    TextBox		txtEnvironmentCharges		TextAlign: Right
    Label			Total Charges:
    TextBox		txtTotalCharges		TextAlign: Right
    GroupBox			Taxes
    Label			Local Taxes:
    TextBox		txtLocalTaxes		TextAlign: Right
    Label			State Taxes:
    TextBox		txtStateTaxes		TextAlign: Right
    GroupBox			Water Bill Payment
    Label			Payment Due Date:
    DateTimePicker		dtpPaymentDueDate
    Label			Amount Due:
    TextBox		txtAmountDue		TextAlign: Right
    Label			Late Payment Due Date:
    DateTimePicker		dtpLatePaymentDueDate
    Label			Late Amount Due:
    TextBox		txtLateAmountDue		TextAlign: Right
    Button		btnSaveWaterBill	Save Water Bill
    Button		btnClose	Close

12. On the form, double-click the Find Customer Account button
13. Return to the Water Bills - Create form and double-click the Evaluate Water Bill button
14. Return to the Water Bills - Create form and double-click the Save Water Bill button
15. Return to the form and double-click the Close button
16. Change the document as follows:

    using StellarWaterPoint2.Models;
    using System.Xml.Serialization;
    
    namespace StellarWaterPoint2.WaterBills
    {
        public partial class Create : Form
        {
            public Create()
            {
                InitializeComponent();
            }
    
            private void btnFindCustomerAccount_Click(object sender, EventArgs e)
            {
                if (string.IsNullOrEmpty(mtbAccountNumber.Text))
                {
                    MessageBox.Show("You must type an account number for a customer.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                Customer? client          = null;
                List<Customer> clients    = new List<Customer>();
                string strCustomers       = @"E:\Stellar Water Point\Customers.xml";
                XmlSerializer xsCustomers = new XmlSerializer(typeof(List<Customer>));
    
                FileInfo fiCustomers = new FileInfo(strCustomers);
    
                if (fiCustomers.Exists == true)
                {
                    using (TextReader trCustomers = new StreamReader(fiCustomers.FullName))
                    {
                        clients = (List<Customer>)xsCustomers.Deserialize(trCustomers)!;
    
                        client  = clients.Find(cust => cust.AccountNumber == mtbAccountNumber.Text)!;
                    }
                }
    
                if (client is null)
                {
                    MessageBox.Show("There is no customer with that account number in our system.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                string strMeterNumber = client.MeterNumber!;
                txtCustomerName.Text  = client.FirstName + " " + client.LastName;
                txtAddress.Text       = client.Address;
                txtCity.Text          = client.City;
                txtCounty.Text        = client.County;
                txtState.Text         = client.State;
                mtbZIPCode.Text       = client.ZIPCode;
    
                WaterMeter? meter            = null;
                List<WaterMeter> waterMeters = new List<WaterMeter>();
                string strWaterMeters        = @"E:\Stellar Water Point\WaterMeters.xml";
                XmlSerializer xsWaterMeters  = new XmlSerializer(typeof(List<WaterMeter>));
    
                FileInfo fiWaterMeters = new FileInfo(strWaterMeters);
    
                if (fiWaterMeters.Exists == true)
                {
                    using (TextReader trWaterMeters = new StreamReader(fiWaterMeters.FullName))
                    {
                        waterMeters = (List<WaterMeter>)xsWaterMeters.Deserialize(trWaterMeters)!;
    
                        meter       = waterMeters.Find(m => m.MeterNumber == strMeterNumber)!;
                    }
                }
    
                txtMeterDetails.Text = meter?.Make + " " +
                                       meter?.Model + " (Meter #: " +
                                       meter?.MeterSize + ")";
            }
    
            private void dtpMeterReadingEndDate_ValueChanged(object sender, EventArgs e)
            {
                TimeSpan tsDays     = dtpMeterReadingEndDate.Value - dtpMeterReadingStartDate.Value;
    
                txtBillingDays.Text = tsDays.Days.ToString();
            }
    
            private void btnEvaluateWaterBill_Click(object sender, EventArgs e)
            {
                double counterStart = 0, counterEnd = 0;
    
                try
                {
                    counterStart    = double.Parse(txtCounterReadingStart.Text);
                }
                catch (FormatException feCRStart)
                {
                    MessageBox.Show("There was a problem with the value of the " +
                                    "Counter Reading Start. The error produced is: " + feCRStart.Message,
                                    "Stellar Water Point", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
    
                try
                {
                    counterEnd = double.Parse(txtCounterReadingEnd.Text);
                }
                catch (FormatException feCREnd)
                {
                    MessageBox.Show("There was a problem with the value of the " +
                                    "Counter Reading End. The error produced is: " + feCREnd.Message,
                                    "Stellar Water Point", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
    
                double consumption            = counterEnd   - counterStart;
                double gallons                = consumption  * 748.05;
                double firstTier              = gallons      * (48.00 / 10000.00);
                double secondTier             = gallons      * (32.00 / 10000.00);
                double lastTier               = gallons      * (20.00 / 10000.00);
                double waterCharges           = firstTier    + secondTier + lastTier;
                double sewerCharges           = waterCharges * 28.65  / 100;
                double envCharges             = waterCharges * 0.22184;
                double totalCharges           = waterCharges + sewerCharges + envCharges;
                double localTaxes             = totalCharges * 0.06148;
                double stateTaxes             = totalCharges * 0.01374;
                double amtDue                 = totalCharges + localTaxes   + stateTaxes;
    
                TimeSpan tsPaymentDueDate     = new TimeSpan(15, 0, 0, 0);
    
                txtTotalCCF.Text              = consumption.ToString();
                txtTotalGallons.Text          = gallons.ToString("F");
                txtFirstTierConsumption.Text  = firstTier.ToString("F");
                txtSecondTierConsumption.Text = secondTier.ToString("F");
                txtLastTierConsumption.Text   = lastTier.ToString("F");
                txtWaterCharges.Text          = waterCharges.ToString("F");
                txtSewerCharges.Text          = sewerCharges.ToString("F");
                txtEnvironmentCharges.Text    = envCharges.ToString("F");
                txtTotalCharges.Text          = totalCharges.ToString("F");
                txtLocalTaxes.Text            = localTaxes.ToString("F");
                txtStateTaxes.Text            = stateTaxes.ToString("F");
                dtpPaymentDueDate.Value       = dtpMeterReadingEndDate.Value + tsPaymentDueDate;
                txtAmountDue.Text             = amtDue.ToString("F");
                dtpLatePaymentDueDate.Value   = dtpMeterReadingEndDate.Value + new TimeSpan(30, 0, 0, 0);
                txtLateAmountDue.Text         = (amtDue + 8.95).ToString("F");
            }
    
            private void btnSaveWaterBill_Click(object sender, EventArgs e)
            {
                if (string.IsNullOrEmpty(txtBillNumber.Text))
                {
                    MessageBox.Show("You must type a bill number." +
                                    "Otherwise, the account cannot be saved.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                if (string.IsNullOrEmpty(txtCounterReadingStart.Text))
                {
                    MessageBox.Show("You must enter the start value of the water bill counter." +
                                    "Otherwise, the account cannot be saved.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                if (string.IsNullOrEmpty(mtbAccountNumber.Text))
                {
                    MessageBox.Show("You must type an account number of a customer." +
                                    "Otherwise, the account cannot be saved.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                List<WaterBill> bills      = new List<WaterBill>();
                string strWaterBills       = @"E:\Stellar Water Point\WaterBills.xml";
                XmlSerializer xsWaterBills = new XmlSerializer(typeof(List<WaterBill>));
    
                FileInfo fiWaterBills      = new FileInfo(strWaterBills);
    
                if (fiWaterBills.Exists == true)
                {
                    using (TextReader trWaterBills = new StreamReader(fiWaterBills.FullName))
                    {
                        bills = (List<WaterBill>)xsWaterBills.Deserialize(trWaterBills)!;
                    }
                }
    
                WaterBill bill = new WaterBill()
                {
                    BillNumber            =    int.Parse(txtBillNumber.Text),
                    AccountNumber         =              mtbAccountNumber.Text,
                    MeterReadingStartDate =              dtpLatePaymentDueDate.Value.ToShortDateString(),
                    MeterReadingEndDate   =              dtpMeterReadingEndDate.Value.ToShortDateString(),
                    BillingDays           =    int.Parse(txtBillingDays.Text),
                    CounterReadingStart   = double.Parse(txtCounterReadingStart.Text),
                    CounterReadingEnd     = double.Parse(txtCounterReadingEnd.Text),
                    TotalGallons          = double.Parse(txtTotalGallons.Text),
                    TotalCCF              = double.Parse(txtTotalCCF.Text),
                    FirstTierConsumption  = double.Parse(txtFirstTierConsumption.Text),
                    SecondTierConsumption = double.Parse(txtSecondTierConsumption.Text),
                    LastTierConsumption   = double.Parse(txtLastTierConsumption.Text),
                    WaterCharges          = double.Parse(txtWaterCharges.Text),
                    SewerCharges          = double.Parse(txtSewerCharges.Text),
                    EnvironmentCharges    = double.Parse(txtEnvironmentCharges.Text),
                    TotalCharges          = double.Parse(txtTotalCharges.Text),
                    LocalTaxes            = double.Parse(txtLocalTaxes.Text),
                    StateTaxes            = double.Parse(txtStateTaxes.Text),
                    AmountDue             = double.Parse(txtAmountDue.Text),
                    PaymentDueDate        =              dtpPaymentDueDate.Value.ToShortDateString(),
                    LateAmountDue         = double.Parse(txtLateAmountDue.Text),
                    LatePaymentDueDate    =              dtpLatePaymentDueDate.Value.ToShortDateString()
                };
    
                bills.Add(bill);
    
                using (TextWriter twWaterBills = new StreamWriter(fiWaterBills.FullName))
                {
                    xsWaterBills.Serialize(twWaterBills, bills);
                }
    
                Close();
            }
    
            private void btnClose_Click(object sender, EventArgs e)
            {
                Close();
            }
        }
    }

17. To create a new form, on the main menu, click Project and click Form (Windows Forms)...
18. Type Details as the name of the form
19. Click Add
20. Make that form the same size as the New Water Bill form
21. Select everything on the New Water Bill form. Copy that selection and paste it in the new Water Bill - Details form
22. On the Water Bill - Details form, delete the Find Customer Account, the Evaluate Water Bill, and the Save Water Bill buttons
23. Add a button as follows:

    

    Control		(Name)	Text
    Button		btnFindWaterBill	Find Water &Bill

24. On the form, double-click the Find Water Bill button
25. Return tp the form and double-click the Close button
26. Change the document as follows:

    using StellarWaterPoint20.Models;
    using System.Xml.Serialization;
    
    namespace StellarWaterPoint20.WaterBills
    {
        public partial class Details : Form
        {
            public Details()
            {
                InitializeComponent();
            }
    
            private void btnFindWaterBill_Click(object sender, EventArgs e)
            {
                if (string.IsNullOrEmpty(txtBillNumber.Text))
                {
                    MessageBox.Show("You must type a bill number.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                WaterBill? bill            = null;
                List<WaterBill> bills      = new List<WaterBill>();
                string strWaterBills       = @"E:\Stellar Water Point\WaterBills.xml";
                XmlSerializer xsWaterBills = new XmlSerializer(typeof(List<WaterBill>));
    
                FileInfo fiWaterBills      = new FileInfo(strWaterBills);
    
                if (fiWaterBills.Exists == true)
                {
                    using (TextReader trWaterBills = new StreamReader(fiWaterBills.FullName))
                    {
                        bills = (List<WaterBill>)xsWaterBills.Deserialize(trWaterBills)!;
    
                        bill  = bills.Find(pay => pay.BillNumber == int.Parse(txtBillNumber.Text))!;
                    }
                }
    
                if (bill is null)
                {
                    MessageBox.Show("There is no water bill with that number in our system.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                mtbAccountNumber.Text         = bill.AccountNumber;
                dtpLatePaymentDueDate.Value   = DateTime.Parse(bill.MeterReadingStartDate!);
                dtpMeterReadingEndDate.Value  = DateTime.Parse(bill.MeterReadingEndDate!);
                txtBillingDays.Text           = bill.BillingDays.ToString();
                txtCounterReadingStart.Text   = bill.CounterReadingStart.ToString();
                txtCounterReadingEnd.Text     = bill.CounterReadingEnd.ToString();
                txtTotalGallons.Text          = bill.TotalGallons.ToString();
                txtTotalCCF.Text              = bill.TotalCCF.ToString();
                txtFirstTierConsumption.Text  = bill.FirstTierConsumption.ToString();
                txtSecondTierConsumption.Text = bill.SecondTierConsumption.ToString();
                txtLastTierConsumption.Text   = bill.LastTierConsumption.ToString();
                txtWaterCharges.Text          = bill.WaterCharges.ToString();
                txtSewerCharges.Text          = bill.SewerCharges.ToString();
                txtEnvironmentCharges.Text    = bill.EnvironmentCharges.ToString();
                txtTotalCharges.Text          = bill.TotalCharges.ToString();
                txtLocalTaxes.Text            = bill.LocalTaxes.ToString();
                txtStateTaxes.Text            = bill.StateTaxes.ToString();
                txtAmountDue.Text             = bill.AmountDue.ToString();
                dtpPaymentDueDate.Value       = DateTime.Parse(bill.PaymentDueDate!);
                txtLateAmountDue.Text         = bill.LateAmountDue.ToString();
                dtpLatePaymentDueDate.Value   = DateTime.Parse(bill.LatePaymentDueDate!);
    
                Customer? client              = null;
                string? strMeterNumber        = string.Empty;
                List<Customer> clients        = new List<Customer>();
                string strCustomers           = @"E:\Stellar Water Point\Customers.xml";
                XmlSerializer xsCustomers     = new XmlSerializer(typeof(List<Customer>));
    
                FileInfo fiCustomers          = new FileInfo(strCustomers);
    
                using (TextReader trCustomers = new StreamReader(fiCustomers.FullName))
                {
                    clients = (List<Customer>)xsCustomers.Deserialize(trCustomers)!;
    
                    client  = clients.Find(cust => cust.AccountNumber == mtbAccountNumber.Text)!;
    
                    strMeterNumber           = client.MeterNumber!;
                    txtCustomerName.Text     = client.FirstName + " " + client.LastName;
                    txtAddress.Text          = client.Address;
                    txtCity.Text             = client.City;
                    txtCounty.Text           = client.County;
                    txtState.Text            = client.State;
                    mtbZIPCode.Text          = client.ZIPCode;
                }
    
                WaterMeter? meter            = null;
                List<WaterMeter> waterMeters = new List<WaterMeter>();
                string strWaterMeters        = @"E:\Stellar Water Point\WaterMeters.xml";
                XmlSerializer xsWaterMeters  = new XmlSerializer(typeof(List<WaterMeter>));
    
                FileInfo fiWaterMeters       = new FileInfo(strWaterMeters);
    
                using (TextReader trWaterMeters = new StreamReader(fiWaterMeters.FullName))
                {
                    waterMeters = (List<WaterMeter>)xsWaterMeters.Deserialize(trWaterMeters)!;
    
                    meter       = waterMeters.Find(m => m.MeterNumber == strMeterNumber)!;
    
                    txtMeterDetails.Text = meter?.Make + " " +
                                           meter?.Model + " (Meter #: " +
                                           meter?.MeterSize + ")";
                }
            }
    
            private void btnClose_Click(object sender, EventArgs e)
            {
                Close();
            }
        }
    }

Finalizing the Application

An application must provide intuitive tools for the users. To make this happen, we will create a menu for the application.

Practical Learning: Laying Out the Documents

1. In the Solution Explorer, right-click Form1.cs and click Rename
2. Change the name to WaterDistribution.cs
3. Press Enter three times to apply the name and display the form
4. In the Properties window, change the following characteristics:
   IsMdiContainer: True
   StartPosition: CenterScreen
   Text: Stellar Water Point

   

1. In the Solution Explorer, double-click WaterDistribution.cs to display the main form of the application
2. In the Toolbox, expand Menus & Toolbars
3. In the Menus & Toolbars section of the Toolbox, click MenuStrip and click the form
4. In the Properties window, click (Name) and type msMainMenu
5. Still in the Properties window, click Items and click its button
6. Using the Add button, create three items as follows:

   Text	(Name)
   &File	miFile
   Water &Bills	miWaterBills
   &Customers	miCustomers
   Water &Meters	miWaterMeters
   &Window	miWindow
   &Help	miHelp

7. In the Members list of the Items Collection Editor, click miFile
8. In the right list, click DropDownItems and click its button
9. Using the Add button, create two items as follows:

   Text	(Name)	Shortcuts
   E&xit	miFileExit	Alt + F4

10. On the Items Collection Editor (miFile.DropDownItems) dialog box, click OK
11. In the Members list of the Items Collection Editor, click miWaterBills
12. In the right list, click DropDownItems and click its button
13. Using the Add button, create two items as follows:

    Text	(Name)	Shortcuts
    &Prepare Water Bill...	miWaterBillsCreate	Ctrl+Shift+B
    &View Water Bill...	miWaterBillsView	Ctrl+Shift+V

14. On the Items Collection Editor (miWaterBills.DropDownItems) dialog box, click OK
15. In the Members list of the Items Collection Editor, click miCustomers
16. In the right list, click DropDownItems and click its button
17. Using the Add button, create two items as follows:

    Text	(Name)	Shortcuts
    &Create Customer Account...	miCustomersCreate	Ctrl+Shift+C
    &Edit Customer Account...	miCustomersEditor	Ctrl+Shift+E
    &Delete Customer Account...	miCustomersDelete	Ctrl+Shift+D
    	tsCustomersSeparator
    &View All Accounts...	miCustomerViewAll	Ctrl+Shift+A

18. On the Items Collection Editor (miCustomers.DropDownItems) dialog box, click OK
19. In the Members list of the Items Collection Editor, click miWaterMeters
20. In the right list, click DropDownItems and click its button
21. Using the Add button, create two items as follows:

    Text	(Name)	Shortcuts
    &Setup Water Meter...	miWaterMetersCreate	Ctrl+Shift+W
    Edit &Water Meter...	miWaterMetersEditor	Ctrl+Shift+I
    De&lete Water Meter...	miWaterMetersCreate	Ctrl+Shift+R
    	tsWaterMetersSeparator
    View All Wate&r Meters...	miWaterMeterViewAll	Ctrl+Shift+T

22. On the Items Collection Editor (miWaterMeters.DropDownItems) dialog box, click OK
23. In the Members list of the Items Collection Editor, click miWindow
24. In the right list, click DropDownItems and click its button
25. Using the Add button, create two items as follows:

    Text	(Name)
    &Arrange	miWindowArrange
    &Cascade	miWindowCascade
    Tile &Horizontal	miWindowTileHorizontal
    Tile &Vertical	mnuWindowTileVertical

26. On the Items Collection Editor (miWindow.DropDownItems) dialog box, click OK
27. In the Members list of the Items Collection Editor, click miHelp
28. In the right list, click DropDownItems and click its button
29. Using the Add button, create an item as follows:

    Text	(Name)	Shortcuts
    &About Stellar Water Point...	miHelpAbout	Ctrl+F1

30. On the Items Collection Editor (miHelp.DropDownItems) dialog box, click OK
31. On the Items Collection Editor dialog box, click OK
32. On the Stellar Water Point form, click the Water Bills menu item and double-click Prepare Water Bill...
33. Return to the Stellar Water Point form
34. On the Stellar Water Point form, below Prepare Water Bill..., double-click View Water Bill...
35. Return to the Stellar Water Point form
36. Click the Customers menu item and double-click Create Customer Account...
37. Return to the Stellar Water Point form and, below Create Customer Account..., double-click Edit Customer Account...
38. Return to the Stellar Water Point form and double-click Delete Customer Account...
39. Return to the Stellar Water Point form and double-click View All Accounts...
40. Return to the Stellar Water Point form
41. Click the Water Meters menu item and double-click Setup Water Meter...
42. Return to the Stellar Water Point form and, below Setup Water Meter..., double-click Edit Water Meter...
43. Return to the Stellar Water Point form and double-click Delete Water Meter...
44. Return to the Stellar Water Point form and double-click View All Water Meters...
45. Return to the Stellar Water Point form
46. Click the Window menu item and double-click Arrange
47. Return to the Stellar Water Point form and, below Arrange, double-click Cascade
48. Return to the Stellar Water Point form and, below Cascade, double-click Tile Horizontal
49. Return to the Stellar Water Point form and, below Tile Horizontal, double-click Tile Vertical
50. Return to the Stellar Water Point form
51. Click the Help menu item and double-click About Stellar Water Point...
52. Return to the Stellar Water Point form
53. Click the File menu item and double-click Exit
54. Change the document as follows:

    namespace StellarWaterPoint2
    {
        public partial class WaterDistribution : Form
        {
            public static bool MetersDisplaying;
            public static bool MeterEditorDisplaying;
            public static bool MeterDeleteDisplaying;
            public static bool MeterCreateDisplaying;
    
            public static bool ClientsDisplaying;
            public static bool ClientEditorDisplaying;
            public static bool ClientDeleteDisplaying;
            public static bool ClientCreateDisplaying;
    
            private WaterMeters.Manage meters;
            private WaterMeters.Editor meterEditor;
            private WaterMeters.Create meterCreate;
            private WaterMeters.Delete meterDelete;
    
            private Customers.ViewAll clients;
            private Customers.Editor clientEditor;
            private Customers.Create clientCreate;
            private Customers.Delete clientDelete;
    
            public WaterDistribution()
            {
                InitializeComponent();
    
                MetersDisplaying = false;
                MeterEditorDisplaying = false;
                MeterCreateDisplaying = false;
                MeterDeleteDisplaying = false;
    
                ClientsDisplaying = false;
                ClientEditorDisplaying = false;
                ClientCreateDisplaying = false;
                ClientDeleteDisplaying = false;
                
                meters = new WaterMeters.Manage();
                meterEditor = new WaterMeters.Editor();
                meterCreate = new WaterMeters.Create();
                meterDelete = new WaterMeters.Delete();
    
                clients = new Customers.ViewAll();
                clientEditor = new Customers.Editor();
                clientCreate = new Customers.Create();
                clientDelete = new Customers.Delete();
            }
    
            private void miWaterBillsCreate_Click(object sender, EventArgs e)
            {
                WaterBills.Create bill = new WaterBills.Create();
    
                bill.ShowDialog();
            }
    
            private void miWaterBillsDetails_Click(object sender, EventArgs e)
            {
                WaterBills.Details details = new WaterBills.Details();
    
                details.ShowDialog();
            }
    
            private void miCustomersCreate_Click(object sender, EventArgs e)
            {
                if (ClientCreateDisplaying == false)
                {
                    clientCreate = new();
                    clientCreate.MdiParent = this;
                    clientCreate.Show();
    
                    ClientCreateDisplaying = true;
                }
                else
                {
                    clientCreate.BringToFront();
                }
            }
    
            private void miCustomersEditor_Click(object sender, EventArgs e)
            {
                if (ClientEditorDisplaying == false)
                {
                    clientEditor = new();
                    clientEditor.MdiParent = this;
                    clientEditor.Show();
    
                    ClientEditorDisplaying = true;
                }
                else
                {
                    clientEditor.BringToFront();
                }
            }
    
            private void miCustomersDelete_Click(object sender, EventArgs e)
            {
                if (ClientDeleteDisplaying == false)
                {
                    clientDelete = new();
                    clientDelete.MdiParent = this;
                    clientDelete.Show();
    
                    ClientDeleteDisplaying = true;
                }
                else
                {
                    clientDelete.BringToFront();
                }
            }
    
            private void miCustomerViewAll_Click(object sender, EventArgs e)
            {
                if (ClientsDisplaying == false)
                {
                    clients = new();
                    clients.MdiParent = this;
                    clients.Show();
    
                    ClientsDisplaying = true;
                }
                else
                {
                    clients.BringToFront();
                }
            }
    
            private void miWaterMetersCreate_Click(object sender, EventArgs e)
            {
                if (MeterCreateDisplaying == false)
                {
                    meterCreate = new();
                    meterCreate.MdiParent = this;
                    meterCreate.Show();
    
                    MeterCreateDisplaying = true;
                }
                else
                {
                    meterCreate.BringToFront();
                }
            }
    
            private void miWaterMetersEditor_Click(object sender, EventArgs e)
            {
                if (MeterEditorDisplaying == false)
                {
                    meterEditor = new();
                    meterEditor.MdiParent = this;
                    meterEditor.Show();
    
                    MeterEditorDisplaying = true;
                }
                else
                {
                    meterEditor.BringToFront();
                }
            }
    
            private void miWaterMeterViewAll_Click(object sender, EventArgs e)
            {
                if (MetersDisplaying == false)
                {
                    meters = new WaterMeters.Manage();
    
                    meters.MdiParent = this;
                    meters.Show();
    
                    MetersDisplaying = true;
                }
                else
                {
                    meters.BringToFront();
                }
            }
    
            private void miWaterMetersDelete_Click(object sender, EventArgs e)
            {
                if (MeterDeleteDisplaying == false)
                {
                    meterDelete = new();
                    meterDelete.MdiParent = this;
                    meterDelete.Show();
    
                    MeterDeleteDisplaying = true;
                }
                else
                {
                    meterDelete.BringToFront();
                }
            }
    
            private void miWindowArrange_Click(object sender, EventArgs e)
            {
                LayoutMdi(MdiLayout.ArrangeIcons);
            }
    
            private void miWindowCascade_Click(object sender, EventArgs e)
            {
                LayoutMdi(MdiLayout.Cascade);
            }
    
            private void miWindowTileHorizontal_Click(object sender, EventArgs e)
            {
                LayoutMdi(MdiLayout.TileHorizontal);
            }
    
            private void miWindowTileVertical_Click(object sender, EventArgs e)
            {
                LayoutMdi(MdiLayout.TileVertical);
            }
    
            private void miHelpAbout_Click(object sender, EventArgs e)
            {
                AboutSWP about = new AboutSWP();
                about.ShowDialog();
            }
    
            private void miFileExit_Click(object sender, EventArgs e)
            {
                Close();
            }
        }
    }

55. In the Solution Explorer, below Customers, double-click Create
56. On the Customers Create form, double-click the Find Water Meter button
57. Return to the Customers Create form and double-click the Save Customer Account button
58. Return to the Customers Create form and click an unoccupied area of the form
59. In the Solution Explorer, click the Events button
60. While the Customers Create form is selected, in the Events section of the Properties window, double-click Activated
61. Return to the Customers Create form and, in the Events section of the Properties window, double-click FormClosing
62. Implement the events as follows:

    using System.Xml.Serialization;
    using StellarWaterPoint2.Models;
    
    namespace StellarWaterPoint2.Customers
    {
        public partial class Create : Form
        {
            public Create()
            {
                InitializeComponent();
            }
    
            private void btnFindWaterMeter_Click(object sender, EventArgs e)
            {
                if (string.IsNullOrEmpty(mtbMeterNumber.Text))
                {
                    MessageBox.Show("You must type a number for a water meter.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                WaterMeter? meter = null;
                List<WaterMeter> waterMeters = new List<WaterMeter>();
                string strWaterMeters = @"E:\Stellar Water Point\WaterMeters.xml";
                XmlSerializer xsWaterMeters = new XmlSerializer(typeof(List<WaterMeter>));
    
                FileInfo fiWaterMeters = new FileInfo(strWaterMeters);
    
                if (fiWaterMeters.Exists == true)
                {
                    using (TextReader trWaterMeters = new StreamReader(fiWaterMeters.FullName))
                    {
                        waterMeters = (List<WaterMeter>)xsWaterMeters.Deserialize(trWaterMeters)!;
    
                        meter       = waterMeters.Find(m => m.MeterNumber == mtbMeterNumber.Text)!;
                    }
                }
    
                if (meter is null)
                {
                    MessageBox.Show("There is no water meter with that number in our system.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                txtMeterDetails.Text = meter.Make + " " +
                                       meter.Model + " (Meter #: " +
                                       meter.MeterSize + ")";
            }
    
            private void btnSaveCustomerAccount_Click(object sender, EventArgs e)
            {
                if (string.IsNullOrEmpty(mtbAccountNumber.Text))
                {
                    MessageBox.Show("You must type an account number of a customer." +
                                    "Otherwise, the account cannot be saved.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                List<Customer> clients    = new List<Customer>();
                string strCustomers       = @"E:\Stellar Water Point\Customers.xml";
                XmlSerializer xsCustomers = new XmlSerializer(typeof(List<Customer>));
    
                FileInfo fiCustomers = new FileInfo(strCustomers);
    
                if (fiCustomers.Exists == true)
                {
                    using (TextReader trCustomers = new StreamReader(fiCustomers.FullName))
                    {
                        clients = (List<Customer>)xsCustomers.Deserialize(trCustomers)!;
                    }
                }
    
                Customer client = new Customer()
                {
                    AccountNumber = mtbAccountNumber.Text,
                    MeterNumber   = mtbMeterNumber.Text,
                    FirstName     = txtFirstName.Text,
                    LastName      = txtLastName.Text,
                    Address       = txtAddress.Text,
                    City          = txtCity.Text,
                    County        = txtCounty.Text,
                    State         = txtState.Text,
                    ZIPCode       = mtbZIPCode.Text
                };
    
                clients.Add(client);
    
                using (TextWriter twCustomers = new StreamWriter(fiCustomers.FullName))
                {
                    xsCustomers.Serialize(twCustomers, clients);
                }
    
                Close();
            }
    
            private void Create_FormClosing(object sender, FormClosingEventArgs e)
            {
                if (WaterDistribution.ClientCreateDisplaying == true)
                {
                    WaterDistribution.ClientCreateDisplaying = false;
                    Close();
                }
            }
        }
    }

63. In the Solution Explorer, below Customers, double-click Delete
64. On the Customers Create form, double-click the Find Water Meter button
65. Return to the Customers Create form and double-click the Close button
66. Change the document as follows:

    using System.Xml.Serialization;
    using StellarWaterPoint20.Models;
    
    namespace StellarWaterPoint20.Customers
    {
        public partial class Delete : Form
        {
            public Delete()
            {
                InitializeComponent();
            }
    
            private void btnFindCustomer_Click(object sender, EventArgs e)
            {
                if (string.IsNullOrEmpty(mtbAccountNumber.Text))
                {
                    MessageBox.Show("You must type an account number for a customer.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                Customer? client = null;
                List<Customer> clients = new List<Customer>();
                string strCustomers = @"E:\Stellar Water Point\Customers.xml";
                XmlSerializer xsCustomers = new XmlSerializer(typeof(List<Customer>));
    
                FileInfo fiCustomers = new FileInfo(strCustomers);
    
                if (fiCustomers.Exists == true)
                {
                    using (TextReader trCustomers = new StreamReader(fiCustomers.FullName))
                    {
                        clients = (List<Customer>)xsCustomers.Deserialize(trCustomers)!;
    
                        client = clients.Find(cust => cust.AccountNumber == mtbAccountNumber.Text)!;
                    }
                }
    
                if (client is null)
                {
                    MessageBox.Show("There is no customer with that account number in our system.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                mtbMeterNumber.Text = client.MeterNumber!;
                txtFirstName.Text   = client.FirstName;
                txtLastName.Text    = client.LastName;
                txtAddress.Text     = client.Address;
                txtCity.Text        = client.City;
                txtCounty.Text      = client.County;
                txtState.Text       = client.State;
                mtbZIPCode.Text     = client.ZIPCode;
    
                WaterMeter? meter            = null;
                List<WaterMeter> waterMeters = new List<WaterMeter>();
                string strWaterMeters        = @"E:\Stellar Water Point\WaterMeters.xml";
                XmlSerializer xsWaterMeters  = new XmlSerializer(typeof(List<WaterMeter>));
    
                FileInfo fiWaterMeters = new FileInfo(strWaterMeters);
    
                if (fiWaterMeters.Exists == true)
                {
                    using (TextReader trWaterMeters = new StreamReader(fiWaterMeters.FullName))
                    {
                        waterMeters = (List<WaterMeter>)xsWaterMeters.Deserialize(trWaterMeters)!;
    
                        meter = waterMeters.Find(m => m.MeterNumber == mtbAccountNumber.Text)!;
                    }
                }
    
                txtMeterDetails.Text = meter?.Make + " " +
                                       meter?.Model + " (Meter #: " +
                                       meter?.MeterSize + ")";
            }
    
            private void btnDeleteCustomerAccount_Click(object sender, EventArgs e)
            {
                if (string.IsNullOrEmpty(mtbAccountNumber.Text))
                {
                    MessageBox.Show("You must type an account number held by a customer.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                List<Customer>? clients = new List<Customer>();
                string strCustomers = @"E:\Stellar Water Point\Customers.xml";
                XmlSerializer xsCustomers = new XmlSerializer(typeof(List<Customer>));
    
                FileInfo fiCustomers = new FileInfo(strCustomers);
    
                if (fiCustomers.Exists == true)
                {
                    using (TextReader trCustomers = new StreamReader(fiCustomers.FullName))
                    {
                        clients = (List<Customer>)xsCustomers.Deserialize(trCustomers)!;
    
                        foreach (Customer cust in clients)
                        {
                            if (cust.AccountNumber == mtbAccountNumber.Text)
                            {
                                clients.Remove(cust);
                                MessageBox.Show("The customer account will be removed from the system.",
                                                "Stellar Water Point", MessageBoxButtons.OK);
                                break;
                            }
                        }
                    }
                }
    
                TextWriter twCustomers = new StreamWriter(fiCustomers.FullName);
    
                try
                {
                    xsCustomers.Serialize(twCustomers, clients);
                }
                finally
                {
                    twCustomers.Close();
                    Close();
                }
            }
    
            private void Delete_FormClosing(object sender, FormClosingEventArgs e)
            {
                if (WaterDistribution.ClientDeleteDisplaying == true)
                {
                    WaterDistribution.ClientDeleteDisplaying = false;
                    Close();
                }
            }
        }
    }

67. In the Solution Explorer, below Customers, double-click Editor
68. On the Customers Create form, double-click the Find Customer button
69. On the Customers Create form, double-click the Find Water Meter button
70. Return to the Customers Create form and double-click the Update Customer Account button
71. Change the document as follows:

    using System.Xml.Serialization;
    using StellarWaterPoint2.Models;
    
    namespace StellarWaterPoint2.Customers
    {
        public partial class Editor : Form
        {
            public Editor()
            {
                InitializeComponent();
            }
    
            private void btnFindCustomer_Click(object sender, EventArgs e)
            {
                if (string.IsNullOrEmpty(mtbAccountNumber.Text))
                {
                    MessageBox.Show("You must type an account number for a customer.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                Customer? client          = null;
                List<Customer> clients    = new List<Customer>();
                string strCustomers       = @"E:\Stellar Water Point\Customers.xml";
                XmlSerializer xsCustomers = new XmlSerializer(typeof(List<Customer>));
    
                FileInfo fiCustomers = new FileInfo(strCustomers);
    
                if (fiCustomers.Exists == true)
                {
                    using (TextReader trCustomers = new StreamReader(fiCustomers.FullName))
                    {
                        clients = (List<Customer>)xsCustomers.Deserialize(trCustomers)!;
    
                        client = clients.Find(cust => cust.AccountNumber == mtbAccountNumber.Text)!;
                    }
                }
    
                if (client is null)
                {
                    MessageBox.Show("There is no customer with that account number in our system.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                mtbMeterNumber.Text = client.MeterNumber!;
                txtFirstName.Text   = client.FirstName;
                txtLastName.Text    = client.LastName;
                txtAddress.Text     = client.Address;
                txtCity.Text        = client.City;
                txtCounty.Text      = client.County;
                txtState.Text       = client.State;
                mtbZIPCode.Text     = client.ZIPCode;
    
                WaterMeter? meter            = null;
                List<WaterMeter> waterMeters = new List<WaterMeter>();
                string strWaterMeters        = @"E:\Stellar Water Point\WaterMeters.xml";
                XmlSerializer xsWaterMeters  = new XmlSerializer(typeof(List<WaterMeter>));
    
                FileInfo fiWaterMeters = new FileInfo(strWaterMeters);
    
                if (fiWaterMeters.Exists == true)
                {
                    using (TextReader trWaterMeters = new StreamReader(fiWaterMeters.FullName))
                    {
                        waterMeters = (List<WaterMeter>)xsWaterMeters.Deserialize(trWaterMeters)!;
    
                        meter       = waterMeters.Find(m => m.MeterNumber == mtbMeterNumber.Text)!;
                    }
                }
    
                txtMeterDetails.Text = meter?.Make + " " +
                                       meter?.Model + " (Meter #: " +
                                       meter?.MeterSize + ")";
            }
    
            private void btnFindWaterMeter_Click(object sender, EventArgs e)
            {
                if (string.IsNullOrEmpty(mtbMeterNumber.Text))
                {
                    MessageBox.Show("You must type a number for a water meter.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                WaterMeter? meter = null;
                List<WaterMeter> waterMeters = new List<WaterMeter>();
                string strWaterMeters = @"E:\Stellar Water Point\WaterMeters.xml";
                XmlSerializer xsWaterMeters = new XmlSerializer(typeof(List<WaterMeter>));
    
                FileInfo fiWaterMeters = new FileInfo(strWaterMeters);
    
                if (fiWaterMeters.Exists == true)
                {
                    using (TextReader trWaterMeters = new StreamReader(fiWaterMeters.FullName))
                    {
                        waterMeters = (List<WaterMeter>)xsWaterMeters.Deserialize(trWaterMeters)!;
    
                        meter = waterMeters.Find(m => m.MeterNumber == mtbMeterNumber.Text)!;
                    }
                }
    
                if (meter is null)
                {
                    MessageBox.Show("There is no water meter with that number in our system.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                txtMeterDetails.Text = meter.Make + " " +
                                       meter.Model + " (Meter #: " +
                                       meter.MeterSize + ")";
            }
    
            private void btnUpdateCustomerAccount_Click(object sender, EventArgs e)
            {
                if (string.IsNullOrEmpty(mtbAccountNumber.Text))
                {
                    MessageBox.Show("You must type a customer's account number.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                List<Customer> clients = new List<Customer>();
                string strCustomers = @"E:\Stellar Water Point\Customers.xml";
                XmlSerializer xsCustomers = new XmlSerializer(typeof(List<Customer>));
    
                FileInfo fiCustomers = new FileInfo(strCustomers);
    
                if (fiCustomers.Exists == true)
                {
                    using (TextReader trCustomers = new StreamReader(fiCustomers.FullName))
                    {
                        clients = (List<Customer>)xsCustomers.Deserialize(trCustomers)!;
    
                        clients.ForEach(client =>
                        {
                            if (client.AccountNumber == mtbAccountNumber.Text)
                            {
                                client.MeterNumber = mtbMeterNumber.Text;
                                client.FirstName   = txtFirstName.Text;
                                client.LastName    = txtLastName.Text;
                                client.Address     = txtAddress.Text;
                                client.City        = txtCity.Text;
                                client.County      = txtCounty.Text;
                                client.State       = txtState.Text;
                                client.ZIPCode     = mtbZIPCode.Text;
                            }
                        });
                    }
                }
    
                using (TextWriter twCustomers = new StreamWriter(fiCustomers.FullName))
                {
                    xsCustomers.Serialize(twCustomers, clients);
                }
    
                Close();
            }
    
            private void Editor_FormClosing(object sender, FormClosingEventArgs e)
            {
                if (WaterDistribution.ClientEditorDisplaying == true)
                {
                    WaterDistribution.ClientEditorDisplaying = false;
                    Close();
                }
            }
        }
    }

72. In the Solution Explorer, below Customers, double-click ViewAll
73. Click an unoccupied area of the form
74. In the Events section of the Properties window, double-click Activated
75. Return to the form and, in the Events section of the Properties window, double-click FormClosing
76. Change the document as follows:

    using System.Xml.Serialization;
    using StellarWaterPoint2.Models;
    
    namespace StellarWaterPoint2.Customers
    {
        public partial class ViewAll : Form
        {
            public ViewAll()
            {
                InitializeComponent();
            }
    
            private void ShowCustomers()
            {
                List<Customer> clients    = new List<Customer>();
                string strCustomers       = @"E:\Stellar Water Point\Customers.xml";
                XmlSerializer xsCustomers = new XmlSerializer(typeof(List<Customer>));
    
                FileInfo fiCustomers = new FileInfo(strCustomers);
    
                if (fiCustomers.Exists == true)
                {
                    using (TextReader trCustomers = new StreamReader(fiCustomers.FullName))
                    {
                        clients = (List<Customer>)xsCustomers.Deserialize(trCustomers)!;
    
                        int counter = 1;
    
                        lvwCustomers.Items.Clear();
    
                        foreach (Customer client in clients)
                        {
                            ListViewItem lviCustomer = new ListViewItem(counter++.ToString());
    
                            lviCustomer.SubItems.Add(client.AccountNumber);
                            lviCustomer.SubItems.Add(client.MeterNumber);
                            lviCustomer.SubItems.Add(client.FirstName);
                            lviCustomer.SubItems.Add(client.LastName);
                            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);
                        }
                    }
                }
            }
    
            private void ViewAll_Activated(object sender, EventArgs e)
            {
                ShowCustomers();
            }
    
            private void ViewAll_FormClosing(object sender, FormClosingEventArgs e)
            {
                if (WaterDistribution.ClientsDisplaying == true)
                {
                    WaterDistribution.ClientsDisplaying = false;
                    Close();
                }
            }
        }
    }

77. In the Solution Explorer, below WaterMeters, double-click Create
78. On the Water Meters - Create form, double-click the S&ave Water Meter button
79. Return to the form and, in the Events section of the Properties window, double-click FormClosing
80. Implement the events as follows:

    using StellarWaterPoint2.Models;
    using System.Xml.Serialization;
    
    namespace StellarWaterPoint2.WaterMeters
    {
        public partial class Create : Form
        {
            public Create()
            {
                InitializeComponent();
            }
    
            private void btnSaveWaterMeter_Click(object sender, EventArgs e)
            {
                if (string.IsNullOrEmpty(mtbMeterNumber.Text))
                {
                    MessageBox.Show("You must type a meter number. " +
                                    "Otherwise, the water meter cannot be set up.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                List<WaterMeter> waterMeters = new List<WaterMeter>();
                string strWaterMeters = @"E:\Stellar Water Point\WaterMeters.xml";
                XmlSerializer xsWaterMeters = new XmlSerializer(typeof(List<WaterMeter>));
    
                FileInfo fiWaterMeters = new FileInfo(strWaterMeters);
    
                if (fiWaterMeters.Exists == true)
                {
                    using (TextReader trWaterMeters = new StreamReader(fiWaterMeters.FullName))
                    {
                        waterMeters = (List<WaterMeter>)xsWaterMeters.Deserialize(trWaterMeters)!;
                    }
                }
    
                WaterMeter wm = new WaterMeter()
                {
                    MeterNumber = mtbMeterNumber.Text,
                    Make = txtMake.Text,
                    Model = txtModel.Text,
                    MeterSize = txtMeterSize.Text
                };
    
                waterMeters.Add(wm);
    
                using (TextWriter twWaterMeters = new StreamWriter(fiWaterMeters.FullName))
                {
                    xsWaterMeters.Serialize(twWaterMeters, waterMeters);
                }
    
                Close();
            }
    
            private void Create_FormClosing(object sender, FormClosingEventArgs e)
            {
                if (WaterDistribution.MeterCreateDisplaying == true)
                {
                    WaterDistribution.MeterCreateDisplaying = false;
                    Close();
                }
            }
        }
    }

81. In the Solution Explorer, below WaterMeters, double-click Editor
82. Return to the form and double-click the Update Water Meter button
83. Return to the form and click an unoccupied area of the form
84. In the Events section of the Properties window, double-click FormClosing
85. Change the document as follows:

    using StellarWaterPoint2.Models;
    using System.Xml.Serialization;
    
    namespace StellarWaterPoint2.WaterMeters
    {
        public partial class Editor : Form
        {
            public Editor()
            {
                InitializeComponent();
            }
    
            private void btnFindWaterMeter_Click(object sender, EventArgs e)
            {
                if (string.IsNullOrEmpty(mtbMeterNumber.Text))
                {
                    MessageBox.Show("You must type a number for a water meter.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                WaterMeter? meter = null;
                List<WaterMeter> waterMeters = new List<WaterMeter>();
                string strWaterMeters = @"E:\Stellar Water Point\WaterMeters.xml";
                XmlSerializer xsWaterMeters = new XmlSerializer(typeof(List<WaterMeter>));
    
                FileInfo fiWaterMeters = new FileInfo(strWaterMeters);
    
                if (fiWaterMeters.Exists == true)
                {
                    using (TextReader trWaterMeters = new StreamReader(fiWaterMeters.FullName))
                    {
                        waterMeters = (List<WaterMeter>)xsWaterMeters.Deserialize(trWaterMeters)!;
    
                        meter       = waterMeters.Find(m => m.MeterNumber == mtbMeterNumber.Text)!;
                    }
                }
    
                if (meter is null)
                {
                    MessageBox.Show("There is no water meter with that number in our system.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
    
                txtMake.Text      = meter.Make;
                txtModel.Text     = meter.Model;
                txtMeterSize.Text = meter.MeterSize;
            }
    
            private void btnUpdateWaterMeter_Click(object sender, EventArgs e)
            {
                if (string.IsNullOrEmpty(mtbMeterNumber.Text))
                {
                    MessageBox.Show("You must type a number for a water meter.",
                                    "Stellar Water Point", MessageBoxButtons.OK);
                    return;
                }
    
                List<WaterMeter> waterMeters = new List<WaterMeter>();
                string strWaterMeters        = @"E:\Stellar Water Point\WaterMeters.xml";
                XmlSerializer xsWaterMeters  = new XmlSerializer(typeof(List<WaterMeter>));
    
                FileInfo fiWaterMeters = new FileInfo(strWaterMeters);
    
                if (fiWaterMeters.Exists == true)
                {
                    using (TextReader trWaterMeters = new StreamReader(fiWaterMeters.FullName))
                    {
                        waterMeters = (List<WaterMeter>)xsWaterMeters.Deserialize(trWaterMeters)!;
    
                        waterMeters.ForEach(wm =>
                        {
                            if (wm.MeterNumber == mtbMeterNumber.Text)
                            {
                                wm.Make = txtMake.Text;
                                wm.Model = txtModel.Text;
                                wm.MeterSize = txtMeterSize.Text;
                            }
                        });
                    }
                }
    
                using (TextWriter twWaterMeters = new StreamWriter(fiWaterMeters.FullName))
                {
                    xsWaterMeters.Serialize(twWaterMeters, waterMeters);
                }
    
                Close();
            }
    
            private void Editor_FormClosing(object sender, FormClosingEventArgs e)
            {
                if (WaterDistribution.MeterEditorDisplaying == true)
                {
                    WaterDistribution.MeterEditorDisplaying = false;
                    Close();
                }
            }
        }
    }

86. In the Solution Explorer, below WaterMeters, double-click Manage
87. In the Events section of the Properties window, double-click Activated
88. Return to the form and, in the Events section of the Properties window, double-click FormClosing
89. Change the document as follows:

    using System.Xml.Serialization;
    using StellarWaterPoint2.Models;
    
    namespace StellarWaterPoint2.WaterMeters
    {
        public partial class Manage : Form
        {
            public Manage()
            {
                InitializeComponent();
            }
    
            private void ShowWaterMeters()
            {
                string strWaterMeters        = @"E:\Stellar Water Point\WaterMeters.xml";
                List<WaterMeter> waterMeters = new List<WaterMeter>();
                XmlSerializer xsWaterMeters  = new XmlSerializer(typeof(List<WaterMeter>));
    
                FileInfo fiWaterMeters = new FileInfo(strWaterMeters);
    
                if (fiWaterMeters.Exists == true)
                {
                    using (TextReader trWaterMeters = new StreamReader(fiWaterMeters.FullName))
                    {
                        waterMeters = (List<WaterMeter>)xsWaterMeters.Deserialize(trWaterMeters)!;
    
                        int counter = 1;
    
                        lvwWaterMeters.Items.Clear();
    
                        foreach (WaterMeter wm in waterMeters)
                        {
                            ListViewItem lviWaterMeter = new ListViewItem(counter++.ToString());
    
                            lviWaterMeter.SubItems.Add(wm.MeterNumber);
                            lviWaterMeter.SubItems.Add(wm.Make);
                            lviWaterMeter.SubItems.Add(wm.Model);
                            lviWaterMeter.SubItems.Add(wm.MeterSize);
    
                            lvwWaterMeters.Items.Add(lviWaterMeter);
                        }
                    }
                }
            }
    
            private void Manage_Activated(object sender, EventArgs e)
            {
                ShowWaterMeters();
            }
    
            private void Manage_FormClosing(object sender, FormClosingEventArgs e)
            {
                if (WaterDistribution.MetersDisplaying == true)
                {
                    WaterDistribution.MetersDisplaying = false;
                    Close();
                }
            }
        }
    }

Testing the Application

After creating an application, you can test it. Of course, you must first execute it.

Practical Learning: Tesing the Application

1. To execute, on the main menu, click Debug -> Start Without Debugging:

   

2. On the main menu, click Water Meters and click View All Water Meters...:

   

3. On the main menu, click Water Meters and click Setup Water Meter...:

   

4. Enter the value for each of the following records and click Save Water Meter for each:

   Meter #	Make	Model	Meter Size
   392-44-572	Constance Technologies	TG-4822	5/8 Inches
   938-75-869	Stanford Trend	266G	1 1/2 Inches
   588-29-663	Estellano	NCF-226	3/4 Inches
   186-92-805	Lansome	2800	1 1/2 Inches
   799-28-461	Kensa Sons	K-584-L	3/4 Inches
   386-48-057	Estellano	NCF-226	3/4 Inches
   837-06-836	Lansome	7400	5/8 Inches
   207-94-835	Constance Technologies	TG-6220	5/8 Inches
   592-84-957	Kensa Sons	D-497-H	3/4 Inches
   374-06-284	Raynes Energica	i2022	3/4 Inches
   186-99-757	Kensa Sons	M-686-G	1 1/2 Inches
   630-07-055	Lansome	2800	3/4 Inches
   827-50-248	Standard	Trend	428T	3/4 Inches
   470-68-850	Estellano	WRT-482	3/4 Inches
   649-33-505	Constance Technologies	BD-7000	5/8 Inches
   306-82-497	Lansome	9000	3/4 Inches

   

5. On the main menu, click Customers and click View All Accounts:

   

6. On the main menu, click Custoemrs and click Create Customer Account:

   

7. Using the values in the following table, enter an account number, then enter a meter number and click Find Water Meter. Complethe the record with the other values. Then click Save Customer Account:

   Account #	Meter #	First Name	Last Name	Address	City	County	State	ZIP-Code
   9279-570-8394	799-28-461	Thomas	Stones	10252 Broward Ave #D4	Frederick	Frederick	MD	21703-6628
   2068-258-9486	186-92-805	Ericka	Dellaney	4819 East Munk Street	Whitehall	Fulton	PA	17340-2277
   4820-375-2842	392-44-572	Akhil	Koumari	748 Red Hills Rd	Roanoke		VA	24012-9726
   6003-386-3955	374-06-284	Mandiakandara	Marmoudi	539 Avalon Court	Greenwood	Sussex	DE	19950-2288
   9249-379-6848	588-29-663	Richard	Eghert	8280 Sligo North Way	Albright	Preston	WV	26519-4626
   7518-302-6895	207-94-835	Grace	Brenner	4299 Peachtree Court	Rockville	Montgomery	MD	20853-1512
   3028-502-9418	186-99-757	Spencer	Kershaw	338C Grayson Street	Gatchellville	York		PA	17352-3808
   5293-957-3395	386-48-057	Kelly	Davids	10484 Greenway Avenue	Mt Storm	Grant	WV	26739-6242
   2038-413-9680	938-75-869	Amidou	Gomah	2075 Rose Hills Avenue	Washington	DC	20004-1818
   7028-405-9381	306-82-497	Jonathan	Simmings	613 Meadowhill Road	Alonzaville	Shenandoah	VA	22664-2662
   5938-074-5293	592-84-957	Marie	Rath	582G Dunhill Avenue	Lanham	Prince Georges	MD	20706-4422
   1827-395-0203	470-68-850	Sathyavanthara	Khooni	10331 Chryswell Road	Washington		DC	20008-5050
   8027-304-6829	837-06-836	Anthony	Clarcksons	904 Augusta Drive	Blackbird	New Castle	DE	19734-2606
   6699-396-2905	649-33-505	Spencer	Reuter	2850 Burnsweak Avenue	Silver Spring	Montgomery	MD	20910-7272
   7080-583-5947	827-50-248	Sandra	Moffat	663 Sherry Wood East Street	Shimpstown	Franklin	PA	17236-1116

   

8. On the main menu, click Water Bills and click Prepare Water Bill...

   

9. Fill the form with the following values:

   Water Bill #:             847384
   Account #: 	              3028-502-9418
   Meter Reading Start Date: 10/03/2022
   Meter Reading End Date:   01/06/2023
   Counter Reading Start:    16
   Counter Reading End:      21
   Billing Days:             95
   Payment Due Date:         01/21/2023
   Late Payment Due Date:    02/05/2023

   

10. Click Find Customer Account

    

11. Click Evaluate Water Bill

    

12. Click Save Water Bill
13. Follow the same steps to create records as follows:

    Water Bill #	Account #	Meter Reading Start Date	Meter Reading End Date	Counter Reading Start	Counter Reading End	Billing Days	Payment Due Date	Late Payment Due Date
    330820	7028-405-9381	10/03/2022	01/03/2023	9749	9906	92	01/18/2023	02/02/2023
    468550	7518-302-6895	10/05/2022	01/09/2023	96	114	96	01/24/2023	02/08/2023
    148274	9249-379-6848	10/05/2022	01/10/2023	260504	260555	97	01/25/2023	02/09/2023
    326384	2068-258-9486	10/08/2022	01/10/2023	104837	104851	94	01/25/2023	02/09/2023

14. On the main menu, click Water Bills and click View Water Bill
15. In the Water Bill # text box, type 468550
16. Click Find Water Bill
17. On the main menu, click Window and click Tile Vertical
18. On the main menu, click Window and click Tile Horizontal
19. On the main menu, click Window and click Cascade
20. On the main menu, click File and click Exit
21. Close Microsoft Visual Studio

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