RadioButton IsChecked Binding Problem – Conclusions

After I posted my previous post on this subject, I done some research on this issue and I found the following:

1. The binding between the IsChecked property and a property in the “code behind” works in only if the binding is declared inside a Control Template, see code below.
2. When binding between xaml elements the problem does not occur.

<UserControl

    xmlns=“http://schemas.microsoft.com/winfx/2006/xaml/presentation“

    xmlns:x=“http://schemas.microsoft.com/winfx/2006/xaml“

    x:Class=“RadioButtonTest.TemplatedControl“

    Height=“300“ Width=“300“ Template=“{DynamicResource UserControlControlTemplate1}“>

  <UserControl.Resources>

    <BooleanToVisibilityConverter x:Key=“BooleanToVisibilityConverter“/>

    <ControlTemplate x:Key=“UserControlControlTemplate1“ TargetType=“{x:Type UserControl}“>

      <Grid>

        <StackPanel VerticalAlignment=“Top“>

          <StackPanel VerticalAlignment=“Top“>

 

            <RadioButton

                Height=“16“

                HorizontalAlignment=“Left“

                Name=“isEllipse“

 

                IsChecked=“{Binding Path=IsEllipse,

                                        RelativeSource={RelativeSource TemplatedParent},

                                        Mode=TwoWay,

                                        UpdateSourceTrigger=PropertyChanged}“

                Content=“Ellipse“/>

 

            <RadioButton

                Height=“16“

                HorizontalAlignment=“Left“

                Name=“isRectangle“

                Content=“Rectangle“/>

 

          </StackPanel>

          <TextBlock Text=“Binding Visibilty to Radio Button IsChecked “/>

          <TextBlock Text=“property with BooleanToVisibilityConverter:“/>

          <Ellipse x:Name=“EllipseTip“ Fill=“#FF000000“

                  Width=“30“ Height=“30“  StrokeThickness=“1“

                  Visibility=“{Binding Path=IsChecked, Converter={StaticResource BooleanToVisibilityConverter}, ElementName=isEllipse, Mode=Default}“/>

          <Rectangle x:Name=“RectangleTip“ Fill=“#FF000000“

                    Width=“30“ Height=“30“ StrokeThickness=“1“

                      Visibility=“{Binding Path=IsChecked, Converter={StaticResource BooleanToVisibilityConverter}, ElementName=isRectangle, Mode=Default}“/>

          <TextBlock Text=“Binding to SelectionText Property “/>

          <TextBlock Text=“and IsEnabled to rectangle radio button:“/>

          <TextBox Text=“{Binding Path=SelectionText, RelativeSource={RelativeSource TemplatedParent}, Mode=Default}“

          IsEnabled=“{Binding Path=IsChecked, ElementName=isRectangle, Mode=Default}“/>

        </StackPanel>

      </Grid>

    </ControlTemplate>

  </UserControl.Resources>

</UserControl>

I did a sample which uses two similar controls with the difference that one uses a control template and the other do not, and demonstrates the differences while binding to properties on the UserControls (TemplatedControl and NoTemplateControl).

You can download a sample code (VS2008 Beta2 project) here, Remember to change the .DOC extension to .ZIP.