title: WPF Expander Header Mouseover color change
body: <p>I have wpf Expander control and I want change background color of Header when I do mouse over on it.
  Here is my control:</p>
  
  <pre><code>&lt;Expander Margin="0" ExpandDirection="Right"&gt;
      &lt;Expander.Header&gt;
          &lt;StackPanel Orientation="Horizontal" VerticalAlignment="Top"&gt;
              &lt;Image Source="placeholder_imageObject.png"  Stretch="Uniform" Margin="6,0,0,0" Width="36" Height="36" VerticalAlignment="Center"/&gt;
              &lt;ContentPresenter Content="Image" VerticalAlignment="Center" Margin="5,0,0,0"/&gt;
              &lt;Path Data="{StaticResource RightArrowGeometry}" Fill="Black"  Margin="14,0,0,0" VerticalAlignment="Center"&gt;
              &lt;/Path&gt;
          &lt;/StackPanel&gt;
      &lt;/Expander.Header&gt;
      &lt;Grid Margin="10,0,0,0" Background="White"&gt;
          &lt;controls:SymbolController x:Name="dgSymbolControl"&gt;
          &lt;/controls:SymbolController&gt;
      &lt;/Grid&gt;
  &lt;/Expander&gt;
  </code></pre>
  
  <p>Pls Help
  thanks
  Sai</p>