title: Window.loaded fires before the window is fully loaded
body: <p>I have this code:<br>
  <code>Window w = // something</code><br>
  <code>w.Loaded += // some code to take a screenshot of the window</code><br>
  <code>w.Show();</code>  </p>
  
  <p>The Loaded event fires before the window is fully loaded and I get this image:
  <img src="https://i.stack.imgur.com/ILKpK.jpg" alt="Window screenshot"></p>
  
  <p>I could add a <code>Thread.Sleep</code> or something after <code>w.Show()</code> and before the screenshot but I need to run this piece of code for hundreds of windows.<br>
  My question is: Is there another event that fires when the window is fully loaded? or some way to achieve this without putting the thread to sleep.</p>
  
  <p>Thanks</p>