This code creates a CheckBox control in WPF and adds a Checked event handler.
<CheckBox Margin="8,12,12,0" Name="CheckBox1" FontSize="14"
Checked="CheckBox1_Checked" Height="30" VerticalAlignment="Top"
Foreground="Red">
Check Box
</CheckBox>
Here is the code for Checked event handler.
private void CheckBox1_Checked(object sender, RoutedEventArgs e)
{
CheckBox1.Content = "Checked";
}