title: One node at a time, in TreeView
body: <p>I have a tree view like this:</p>
  
  <pre><code>    1.
  
  
        1.1
  
        1.2
  
      2.
  
  
        2.1
  
        2.2
  
  ....
  </code></pre>
  
  <p>what I want to accomplish is when user click a parent node (for example node 1) every other parent nodes are collapse except the selected node( node 1), in other word, only one subtree is expanded at a time.</p>
  
  <p>I am populating the Menu from Database.
  So I use this code in the parent node populating part. </p>
  
  <pre><code>MenuTreeView.Nodes.Add(newNode); 
  newNode.PopulateOnDemand = true; 
  newNode.Collapse();  
  newNode.SelectAction= TreeNodeSelectAction.Expand;
  </code></pre>
  
  <p>But this is not working.</p>