ASP.NET 3.5 For Dummies®

5.2. Pushing for Choices with the RadioButton Control

ASP.NET RadioButton controls work as a team; however, only one player can be "on" at a time. Figure 5-2 shows three RadioButton controls acting as a group. All three share the same GroupName value. When a user clicks the Submit button, an event handler subroutine (refer to the "Bingo! And events" sidebar) executes and reports which radio button is checked.

Figure 5-2. You can select only one radio button in a group at a time.

Follow these steps to create a group of RadioButton controls and display which one a user has pushed:

1. From the Toolbox, add to the ASP.NET page three RadioButton controls, a Button control (Button1) and a Label control (lblText).

2. Set the RadioButton control's ID values to radTo, radMtl, and radVcr; the Text properties to Toronto, Montreal, and Vancouver; and the GroupName properties to cities.

3. Double-click the button to create a handler for the Button control's Click event and use the following code inside the Click event handler subroutine:

   If radTo.Checked Then
       lblText.Text = "Choice: " & radTo.Text
   ElseIf radMtl.Checked Then
       lblText.Text = "Choice: " & radMtl.Text
   ElseIf radVcr.Checked Then
       lblText.Text = "Choice: " & radVcr.Text
   Else
       lblText.Text = "No choice made."
   End If

The code tests whether the Toronto radio button's Checked property is True (that is, whether the button is pushed). If so, it assigns ...