title: Background color for MenuItem not changed on MouseOver
body: <p>I have a Menu with three items and I'm trying to change the background color when the mouse hovers over any of the items.  I've tried the IsMouseOver &amp; IsHighlighted trigger property and neither works.</p>
  
  <p>In my App.xaml:</p>
  
  <pre><code>&lt;Style TargetType="MenuItem" x:Key="MenuItemStyle" &gt;
          &lt;Style.Triggers&gt;
              &lt;Trigger Property="MenuItem.IsHighlighted" Value="true"&gt;
                  &lt;Setter Property="Background" Value="Black"/&gt;
              &lt;/Trigger&gt;
          &lt;/Style.Triggers&gt;          
      &lt;/Style&gt;
  </code></pre>
  
  <p>In my Main.xaml:</p>
  
  <pre><code>&lt;Menu HorizontalAlignment="Left" Height="30" VerticalAlignment="Top" Width="975
            " FontFamily="Tempus Sans ITC" FontSize="16"  &gt;
          &lt;Menu.Background&gt;
              &lt;LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"&gt;
                  &lt;GradientStop Color="#FFC8C8C8" Offset="0"/&gt;
                  &lt;GradientStop Color="Black" Offset="1"/&gt;
              &lt;/LinearGradientBrush&gt;
          &lt;/Menu.Background&gt;
          &lt;Menu.Foreground&gt;
              &lt;SolidColorBrush Color="#FFFFFFFB"/&gt;
          &lt;/Menu.Foreground&gt;
          &lt;MenuItem Header="New" Click="MenuNew_Click" VerticalAlignment="Center" Padding="15,4,8,3" Width="60"&gt;
              &lt;MenuItem.ToolTip&gt;
                  &lt;ToolTip&gt;
                      Add new Park
                  &lt;/ToolTip&gt;
              &lt;/MenuItem.ToolTip&gt;
          &lt;/MenuItem&gt;
          &lt;MenuItem Header="Search" Width="65" Padding="12,4,8,3"  &gt;
              &lt;MenuItem.ToolTip&gt;
                  &lt;ToolTip&gt; Select search option&lt;/ToolTip&gt;
              &lt;/MenuItem.ToolTip&gt;
              &lt;MenuItem Header="Name" Background="Black" FontSize="14" Style="{StaticResource MenuItemStyle}" /&gt;
              &lt;MenuItem Header="ID" Background="Black" FontSize="14"/&gt;
              &lt;MenuItem Header="OwnerName" Background="Black" FontSize="14"/&gt;
          &lt;/MenuItem&gt;          
      &lt;/Menu&gt;    
  </code></pre>