title: Binding visibility of a control to 'Count' of an IEnumerable
body: <p>I have a list of objects contained in an IEnumerable&lt;>.
  I would like to set the visibility of a control based on the count of this list. I have tried:</p>
  
  <pre><code> Visibility="{Binding MyList.Count&gt;0?Collapsed:Visible, Mode=OneWay}"
  </code></pre>
  
  <p>But this doesn't work. I tried binding MyList.Count to the text in a text block to ensure that the count value was correct, and it is. It just doesn't seem to set the visibility correctly. </p>