title: ListView ComputedVerticalScrollBarVisibilityProperty always returns Visible?
body: <p>I have a GridView within a Listview:</p>
  
  <pre><code>&lt;ListView&gt;                    
    &lt;ListView.View&gt;
      &lt;GridView&gt;
        &lt;GridViewColumn Width="100" /&gt;               
        &lt;GridViewColumn Width="130" /&gt;               
        &lt;GridViewColumn Width="130" /&gt;           
      &lt;/GridView&gt;
    &lt;/ListView.View&gt;
  &lt;/ListView&gt;
  </code></pre>
  
  <p>I want to detect when the vertical scrollbar is visible to the user. </p>
  
  <p>For some reason, this line of code always returns <code>Visible</code>, even when the scrollbar is not visible:
  <code>listView.GetValue(ScrollViewer.ComputedVerticalScrollBarVisibilityProperty)</code></p>
  
  <p>What am I doing wrong here?</p>