title: Xaml can't find binding
body: <p>I have a Page that has three child UserControls. I set the DataContext viewmodel resource in the parent Page and the three child controls reference the parents DataContext because all 3 child user controls use the same ViewModel. All good.</p>
  
  <p>However, one of the UserControls is having binding problems (I can see this because of the new XAML debugging feature in Silverlight 5 Beta.) The UserControl in question is an ItemsControl. Inside each Item is a button and 2 text boxes. That button is bound to a Command. The error is that the Button cannot find its binding. The 2 textboxes are binding correctly. The ItemSource of the ItemsControl is bound to a ObservableCollection in the viewmodel.</p>
  
  <p>My Question is this: How can I tell the Button to look for its binding "at a higher level" than the Observable Collection ie: Go to the view model, not your direct parent (the Observable Collection). You can't set the <code>DataContext</code> for the button in the <code>ChildControl</code> because the reference to the view model isnt there. It's in the parent. </p>