title: WPF: TemplateBinding to StrokeThickness of Shape does not work?
body: <p>Looks like the following Ellipse in ControlTemplate does not get the BorderThickness, but why?</p>
  
  <pre><code>&lt;Window.Resources&gt;
      &lt;ControlTemplate x:Key="EllipseControlTemplate" TargetType="{x:Type TextBox}"&gt;
          &lt;Grid&gt;
              &lt;Ellipse 
                  Width="{TemplateBinding ActualWidth}" 
                  Height="{TemplateBinding ActualHeight}" 
                  Stroke="{TemplateBinding Foreground}" 
                  StrokeThickness="{TemplateBinding BorderThickness}" /&gt;
                  &lt;ScrollViewer Margin="0" x:Name="PART_ContentHost" HorizontalAlignment="Center" VerticalAlignment="Center"/&gt;
          &lt;/Grid&gt;
      &lt;/ControlTemplate&gt;
  &lt;/Window.Resources&gt;
  &lt;Grid&gt;
      &lt;TextBox
          Template="{DynamicResource EllipseControlTemplate}" 
          Foreground="Green"
          BorderThickness="15" /&gt;
  &lt;/Grid&gt;
  </code></pre>
  
  <p>TemplateBinding to <code>Foreground</code> works just fine, the ellipse is green. But to <code>StrokeThickness</code> it doesn't seem to work, why?</p>