The <RadioButton> element in XAML is used to create a radio button control in a WPF app.
This article has moved here - Working with a WPF Radio Button Control
The following code example creates a radio button and sets the name, height and width of a RadioButton control. The code also sets the horizontal alignment to left and the vertical alignment to top.
  1. <RadioButton Margin="10,10,0,13" Name="RadioButton1" HorizontalAlignment="Left" VerticalAlignment="Top" Width="150" Height="15" Backgroun d="Yellow " Foreground="Blue">
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  3. </RadioButton>
The RadioButton looks as in following:

XAML RadioButton
Figure 1. RadioButton

The GroupName property of a RadioButton assigns a RadioButton to a group. Only one RadioButton can be in the selected states at once and by selecting a new RadioButton unselects the previous selected RadioButton.

The following code assigns four RadioButton controls to a group called MCSites.
  1. <RadioButton Margin="10,5,0,0" GroupName="MCSites" Background="Yellow" Foreground="Blue" >
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  3. </RadioButton>
  4. <RadioButton Margin="10,5,0,0" GroupName="MCSites" Background="Yellow" Foreground="Orange" >
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  6. </RadioButton>
  7. <RadioButton Margin="10,5,0,0" GroupName="MCSites" Background="Yellow" Foreground="Green" >
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  9. </RadioButton>
  10. <RadioButton Margin="10,5,0,0" GroupName="MCSites" Background="Yellow" Foreground="Purple" >
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  12. </RadioButton>
The output looks as in Figure 2. If you select one RadioButton, the previous RadioButton will be unselected.

XAML RadioButton
Figure 2

RadioButton control has Checked event as default event and raised when you check a radio button. The following code snippet adds the event handler.
  1. <RadioButton Name="Btn1" Margin="10,5,0,0" GroupName="MCSites"
  2. Background="Yellow" Foreground="Blue" Checked="Btn1_Checked">
The following checked event handler sets the foreground and background color of the checked RadioButton and sets black and white for the rest of them.
  1. private void Btn1_Checked(object sender, RoutedEventArgs e)
  2. {
  3. Btn1.Foreground = Brushes.Blue;
  4. Btn1.Background = Brushes.Yellow;
  5. Btn2.Foreground = Brushes.Black;
  6. Btn2.Background = Brushes.White;
  7. Btn3.Foreground = Brushes.Black;
  8. Btn3.Background = Brushes.White;
  9. Btn4.Foreground = Brushes.Black;
  10. Btn4.Background = Brushes.White;
  11. }
New RadioButton group looks as in Figure 3.

XAML RadioButton
Figure 3

The IsChecked property of RadioButton represents whether or not a RadioButton is checked. The following code snippet on a button click event handler finds the text of the selected RadioButton in a group.
  1. private void button1_Click(object sender, RoutedEventArgs e)
  2. {
  3. if( Btn1.IsChecked == true)
  4. MessageBox.Show(Btn1.Content.ToString());
  5. else if (Btn2.IsChecked == true)
  6. MessageBox.Show(Btn2.Content.ToString());
  7. else if (Btn3.IsChecked == true)
  8. MessageBox.Show(Btn3.Content.ToString());
  9. else
  10. MessageBox.Show(Btn4.Content.ToString());
  11. }
This article has moved here: Working with a WPF Radio Button Control