title: How to make a UserControl float over rest of xaml?
body: <p>English is not my primary language, edits are more than welcome.</p>
  
  <p>I've decided to make my own, specialized title bar in my wpf application. So far, everything was going pretty well. Until I had to make something appear under the title bar (at the press of a button for say) but OVER the rest of the window content.</p>
  
  <p>I made a custom Style for every Window that I will want to have my titlebar that goes like this:</p>
  
  <pre><code>&lt;Style x:Key="EditFormStyle" TargetType="Window"&gt;
      &lt;Setter Property="WindowStyle" Value="None"/&gt;
      &lt;Setter Property="Background" Value="White"/&gt;
      &lt;Setter Property="Template"&gt;
          &lt;Setter.Value&gt;
              &lt;ControlTemplate TargetType="Window"&gt;
                  &lt;DockPanel&gt;
                      &lt;c:TitleBar DockPanel.Dock="Top"/&gt;
                      &lt;c:ValidationPannel DockPanel.Dock="Top" Panel.ZIndex="1"/&gt;
                      &lt;ContentPresenter DockPanel.Dock="Bottom" /&gt;
                  &lt;/DockPanel&gt;
              &lt;/ControlTemplate&gt;
          &lt;/Setter.Value&gt;
      &lt;/Setter&gt;
  &lt;/Style&gt;
  </code></pre>
  
  <p>So the content of the Window will be under my TitleBar. This goes perfectly well. Then I wanted to add the ValidationPannel that would display some stuff on the press of a button for Visibility ON/OFF. Pretty usual feature there. The problem is that I want the ValidationPannel to be under the titleBar (which it is) but <strong>over</strong> the rest of the content of the window. As you can see, I tried to use a ZIndex with no success. It keep pushing the content under it.</p>
  
  <p>Is there a way to make the UserControl <em>float</em> over the content, hidding it until I say it to be invisible again?</p>
  
  <p>Thanks in advance.</p>
  
  <p>-->again, feel free to edit.</p>