How to handle RadioButton Checked Event in WPF using VB.NET

Introduction


Here in this article I am explaining that how to Handle RadioButton checked Event in WPF. RadioButton is used for the selection purpose when we want to make a choice from number of items. We can check one RadioButton at a time. In the example we are showing the RadioButton Groups and when we checked any item of group one and press the Button a MessageBox will display with the checked Item name. when we checked the items of Group 2 than on Checked Event a MessageBox will display with the checked item name. The implementation needs a Grid, StackPanel, RadioButton and a Button control.



Getting Started

• Simply create a new WPF application 
• Drag a Grid, StackPanel, RadioButton and a Button control on MainWindow. Your Window will look like below.
  
  
   
• Your MainWindow.xaml page will look like below.
  
  <Window x:Class="MainWindow"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      Title="MainWindow" Height="305" Width="424" Background="Chocolate">
      <Grid Name="grid">
          <Grid.RowDefinitions>
              <RowDefinition Height="Auto"/>
              <RowDefinition Height="*"/>
          </Grid.RowDefinitions>
          <Grid.ColumnDefinitions>
              <ColumnDefinition/>
              <ColumnDefinition/>
          </Grid.ColumnDefinitions>
          <Border Grid.Column="0" BorderBrush="Black" BorderThickness="1" />
          <Border Grid.Column="1" BorderBrush="Black"  BorderThickness="1" />
          <StackPanel Grid.Column="0" HorizontalAlignment="Center" Margin="5" Name="spLeftContainer">
              <TextBlock FontSize="16" Text="Radio Buttons in Group 1" />
              <RadioButton Content="vb1" GroupName="grp1" IsChecked="True" Margin="5" Name="rbnOneA" />
              <RadioButton Content="c#1" GroupName="grp1" Margin="5" Name="rbnOneB" />
              <RadioButton Content="ASP.NET1" GroupName="grp1" Margin="5" Name="rbnOneC" />
              <Separator/>
              <TextBlock FontSize="16" Text="Radio Buttons in Group 2" />
              <RadioButton Checked="RadioButton_Checked" GroupName="grp2" Content="WPF2" IsChecked="True"
                           Margin="5" Name="rbnTwoA" />
              <RadioButton Checked="RadioButton_Checked" GroupName="grp2" Content="SharePoint2" Margin="5"
  Name="rbnTwoB"/>
              <RadioButton Checked="RadioButton_Checked" GroupName="grp2" Content="SilverLight2" Margin="5"
  Name="rbnTwoC"/>
          </StackPanel>
          <StackPanel Grid.Column="1" HorizontalAlignment="Center" Margin="5" Name="spRightContainer">
              <TextBlock FontSize="16" Text="Radio Buttons in Group 1" />
              <RadioButton Content="WCF1" GroupName="grp1" Margin="5" Name="rbnOneD" />
              <RadioButton Content="Crystal Report1" GroupName="grp1" Margin="5" Name="rbnOneE" />
          </StackPanel>
          <Button Content="Display grp1 Selection" Grid.ColumnSpan="2" Grid.Row="1"
  HorizontalAlignment="Center"
                  Margin="10" MaxHeight="25" Click="btn_Click" />
      </Grid>
  </Window>
   
• Then add the below code in Code Behind File.
  
      Private Sub btn_Click(sender As Object, e As RoutedEventArgs)
          Dim radioButton As RadioButton = Nothing
          radioButton = GetCheckedRadioButton(spLeftContainer.Children, "grp1")
          If radioButton Is Nothing Then
              radioButton = GetCheckedRadioButton(spRightContainer.Children, "grp1")
          End If
          MessageBox.Show(Convert.ToString(radioButton.Content) & " checked.", Title)
      End Sub
      Private Function GetCheckedRadioButton(children As UIElementCollection, groupName As [String]) As
          RadioButton
          Return children.OfType(Of RadioButton)().FirstOrDefault(Function(rb) rb.IsChecked = True AndAlso
          rb.GroupName = groupName)
      End Function
      Private Sub RadioButton_Checked(sender As Object, e As RoutedEventArgs)
          If Not Me.IsInitialized Then
              Return
          End If
          Dim radioButton As RadioButton = TryCast(e.OriginalSource, RadioButton) 
          If radioButton IsNot Nothing Then
              MessageBox.Show(Convert.ToString(radioButton.Content) & " checked.", Title)
          End If
      End Sub
   
• Now run your application.
  
  
  

Output