title: How to center Popup in Metro style app in c#
body: <p>Is there any way to show a <strong>Popup</strong> in Windows 8 Metro centered?</p>
  
  <p>Setting <code>VerticalAlignment</code> and <code>HorizontalAlignment</code> to "Center", and <code>VerticsalOffset</code> and <code>HorizontalOffset</code> to 0 causes howing popup with left-up corner in the center of the screen.</p>
  
  <p>Is there any way to do it nicely? </p>
  
  <p>To make this problem harder, this popup has different size in snapped view, where is also should be centered.</p>
  
  <p>Any thoughts?</p>