title: Datacontext of usercontrol is null
body: <p>I have a viewmodel with an observablecollection member.</p>
  
  <p>I created a usercontrol that binds with this collection and for <em>every</em> item in the collection I end up in the user controls constructor. In this constructor the datacontext is null, why is that?</p>
  
  <pre><code>&lt;ItemsControl ItemsSource="{Binding ListOfMyCustomType}"&gt;
  &lt;ItemsControl.ItemTemplate&gt;
      &lt;DataTemplate&gt;
          &lt;uc:Tile DataContext="{Binding Path=.}"&gt;&lt;/uc:Tile&gt;
      &lt;/DataTemplate&gt;
  &lt;/ItemsControl.ItemTemplate&gt;
  &lt;ItemsControl.ItemsPanel&gt;
      &lt;ItemsPanelTemplate&gt;
          &lt;WrapPanel /&gt;
      &lt;/ItemsPanelTemplate&gt;
  &lt;/ItemsControl.ItemsPanel&gt;
  </code></pre>
  
  <p></p>
  
  <p><strong>Edit:</strong><br>
  There are no BindingExpression errors in the debug output.</p>
  
  <p><strong>Edit:</strong><br>
  Solved by Matthias, the datacontext is not available at <em>this time</em>. It will be available when the control is loaded or when the datacontext changes. Thumbs up!</p>
  
  <p>Regards,</p>
  
  <p>Michel</p>