title: How to adjust arrow besides a TreeViewItem?
body: <p>In this <a href="http://www.codeproject.com/Articles/124644/Basic-Understanding-of-Tree-View-in-WPF" rel="nofollow">tutorial</a> a nice example of a <code>TreeView</code> is shown.</p>
  
  <p>Now I would like to have two elements stacked with a <code>StackPanel</code> within a <code>TreeViewItem</code> vertically:</p>
  
  <pre><code>var treeViewItem = new TreeViewItem();
  var stackPanel = new StackPanel() { Orientation = Orientation.Vertical };
  stackPanel.Children.Add(... some text ...);
  stackPanel.Children.Add(... some icon ...);
  treeViewItem.Header = stackPanel;
  </code></pre>
  
  <p>The little arrow besides the <code>TreeViewItem</code> (to display its subitems) is now placed in the middle - between the icon and the text.</p>
  
  <p><strong>Question:</strong> Is it possible to adjust the arrow to the top (besides the icon)?</p>