Microsoft Visual Basic .NET Databases - Lesson 3: Data Binding Windows Controls

	Data Binding Windows Controls

Data Navigation With Windows Controls

Introduction

Although the records of a database are stored in tables, data sheets sometimes provide unfriendly environment for data entry. Of course, to avoid using database tables that can appear boring, you can use the DataGrid control. One of the characteristics of data grids is that they display all of their record set, or at least as much as their width and height can allow. If some fields require much room, a data grid as good looking as it can be, would not be suitable. Imagine that one of the columns contains fields of text of various paragraphs. In this case, the records should be displayed one at a time.

If you want to display one record at a time on a form, you can use Windows controls and provide a means for the user to navigate back and forth in the records.

Practical Learning: Display Data in Windows Controls

To add a new form, on the main menu, click Project -> Add Windows Form...
Replace the Name of the form with Flavors and press Enter
Change its Icon to the above cic.ico and change its Text to Clarksville Ice Cream - Flavors
Set its ShowInTaskbar property to False and its StartPosition to CenterScreen
From the Server Explorer, under the Tables node of CIC1, drag the Flavors table and drop it on the form
On the main menu, click Data -> Generate Dataset...
In the Generate Dataset dialog box, accept the Existing radio button and click OK

Click the Toolbox tab, click Windows Forms, and select the controls to design the form as follows:

Control	Name	DataBindings -> Text dsIceCream - Flavors.	Text	Other Properties
Form
Label			Flavor ID:
TextBox	txtFlavorID	FlavorID		ReadOnly: True TextAlign: Right
Label			Flavor:
TextBox	txtFlavor	Flavor
Label			Composition:
TextBox	txtComposition	Composition		Multiline: True ScrollBars: Vertical
Button	btnClose		Close
Button	btnFirst		\| <
Button	btnPrevious		<
Button	btnNext		>
Button	btnLast		> \|

Double-click an empty area on the form to access its Load event and implement it as follows:

Private Sub Flavors_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.SqlDataAdapter1.Fill(Me.DsIceCream1)
End Sub

In the Class Name combo box, select btnClose. In the Method Name combo box, select Click and implement the event as follows:

Private Sub btnClose_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnClose.Click
        Close()
End Sub

In the Class Name combo box, select btnFirst. In the Method Name combo box, select Click and implement the event as follows:

Private Sub btnFirst_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnFirst.Click
        Me.BindingContext(Me.DsIceCream1, "Flavors").Position = 0
End Sub

In the Class Name combo box, select btnPrevious. In the Method Name combo box, select Click and implement the event as follows:

Private Sub btnPrevious_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnPrevious.Click
        Me.BindingContext(Me.DsIceCream1, "Flavors").Position = _
        Me.BindingContext(Me.DsIceCream1, "Flavors").Position - 1
End Sub

In the Class Name combo box, select btnNext. In the Method Name combo box, select Click and implement the event as follows:

Private Sub btnNext_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnNext.Click
        Me.BindingContext(Me.DsIceCream1, "Flavors").Position = _
        Me.BindingContext(Me.DsIceCream1, "Flavors").Position + 1
End Sub

In the Class Name combo box, select btnLast. In the Method Name combo box, select Click and implement the event as follows:

Private Sub btnLast_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnLast.Click
        Me.BindingContext(Me.DsIceCream1, "Flavors").Position = _
        Me.BindingContext(Me.DsIceCream1, "Flavors").Count - 1
End Sub

Display the first form, Form1.vb [Design]
On the Toolbox, click Button and click under the existing Employees button of the form
Change the new button's Text to Flavors and change its Name to btnFlavors

Double-click the new Flavors button and implement its Click event as follows:

Private Sub btnFlavors_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnFlavors.Click
        Dim frmFlavors As Flavors = New Flavors
        frmFlavors.ShowDialog()
End Sub

Execute the application
On the form, click the Flavors button
Close the forms and return to your programming environment


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