title: How to hide WPF Grid Overflow (like CSS overflow:hidden)
body: <p>I'm currently creating a metro styled app. 
  Because of this I need to extend my client area out of my window to draw the shadow. 
  The problem now is that I have a button set to Margin="0,0,15,15" and of course it draws itself also in this shadow area. How can I hide this? In CSS I would just apply overflow:hidden to the "Content" or the UserControl.</p>
  
  <p><img src="https://i.stack.imgur.com/vdUMc.png" alt="problem"></p>
  
  <p>The basic WPF structure is like this:</p>
  
  <pre><code>&lt;Grid x:Name="LayoutRoot" SnapsToDevicePixels="True" Margin="15" Background="White"&gt;
      &lt;Grid.Effect&gt;
          &lt;DropShadowEffect ShadowDepth="0" BlurRadius="15" Direction="470"/&gt;
      &lt;/Grid.Effect&gt;
          &lt;Grid x:Name="Content"&gt;
          &lt;UserControl&gt;&lt;/UserControl&gt; // This is where the arrow button is with Margin="0,0,15,15"
      &lt;/Grid&gt;
  &lt;/Grid&gt;
  </code></pre>