title: WPF Trigger not working
body: <p>I am trying to use <a href="https://msdn.microsoft.com/en-us/library/system.windows.trigger.aspx" rel="nofollow noreferrer"><code>triggers</code></a> to modify the property of my control.I have a <code>RadioButton</code> and a <code>Border</code>, I want to modify the border <code>Background</code> when the 
  <code>RadioButton</code> IsSelected. So here is my code:</p>
  
  <pre><code>&lt;Border BorderBrush="{DynamicResource MaterialDesignDivider}"&gt;
       &lt;RadioButton IsChecked="{Binding Erase_IsSelected}" Content="E"&gt;
           &lt;RadioButton.Resources&gt;
                &lt;Style TargetType="{x:Type RadioButton}"&gt;
                    &lt;Style.Triggers&gt;
                         &lt;Trigger Property="IsChecked" Value="True"&gt;
                              &lt;Setter Property="Background" Value="{DynamicResource MaterialDesignSelection}" /&gt;
                         &lt;/Trigger&gt;
                    &lt;/Style.Triggers&gt;
                &lt;/Style&gt;
           &lt;/RadioButton.Resources&gt;
       &lt;/RadioButton&gt;
  &lt;/Border&gt;
  </code></pre>
  
  <p>This seems don't work, how should I fix it? Thanks! </p>