title: ASP.NET: How to Create an Expandable Empty TreeNode
body: <p>I need to populate the <code>TreeNode.ChildNodes</code> on the event of <code>TreeView.TreeNodeExpanded</code>. The problem is the node is empty before the event gets fired and it is not expandable in this case and there is no expand icon <strong>[+]</strong> showed next to it.</p>
  
  <p>I want to make the node expandable in case its related object has some children without adding those children to the node. </p>
  
  <p>I thought about adding a virtual child to the node and delete it when it is expanded. Are there any better options ??</p>
  
  <p>Thank you.</p>