title: Make screenshot of DirectX window that is hidden and doesn't have focus
body: <p>How to grab a screenshot of a DirectX window that is not in foreground and doesn't have focus. I want to monitor what happens with application in the background, but without switching to it.</p>
  
  <p>The standard way with <code>PrintWindow</code> doesn't work. You can test that on Unity apps, for example.</p>