title: WPF DropShadowEffect appears on preview but not at runtime
body: <p>So I implemented the following code within my grid:</p>
  
  <pre><code>        &lt;Grid.Effect&gt;
          &lt;DropShadowEffect ShadowDepth="0"
                        Color="Black"
                        Opacity="1"
                        BlurRadius="30" RenderingBias="Quality"/&gt;
         &lt;/Grid.Effect&gt;
  </code></pre>
  
  <p>I can see the shadow appear in the preview; however, when I run it, there is no shadow. So I was wondering if I missed something.</p>
  
  <p>xaml:</p>
  
  <pre><code>&lt;Window x:Class="test.MainWindow"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      Title="MainWindow" Height="350" Width="525" Background="Transparent" WindowStyle="None" AllowsTransparency="True"&gt;
  &lt;Grid&gt;
      &lt;Grid.Effect&gt;
          &lt;DropShadowEffect ShadowDepth="0"
                    Color="Black"
                    Opacity="1"
                    BlurRadius="30" RenderingBias="Quality"/&gt;
      &lt;/Grid.Effect&gt;
  
      &lt;Rectangle Height="350" Width="525" Fill="White" Grid.ColumnSpan="2"&gt;
      &lt;/Rectangle&gt;
  &lt;/Grid&gt;
  </code></pre>
  
  <p></p>
  
  <p>You should see a window with a shadow around the border. Then run it and its gone.</p>
  
  <p><strong>EDIT:</strong> So all I did was add a margin to the rectangle and the drop shadow appears. I'm assuming the window blocks the drop shadow.</p>