I am adding nodes to a TreeView control in Page Load as follows (code abbreviated):

foreach (WorkFlowTask workFlowTask in WorkFlowTasks)
{
   aNode = new TreeNode(workFlowTask.TaskName, workFlowTask.OrderOfCompletion.ToString());
   CreateNode(aNode); //This method adds nodes to their relative node path

   //I have tried a couple things to cause a node to be expanded or collapsed here:
   if (workFlowTask.IsCurrentTask)
   {
      aNode.Expand(); 
      aNode.Expanded = true;

      //and I also had some code to expand Parents:
      // ExpandSelfAndAllParents(aNode);

      //and I also had some code to Select a node (SelectedNodeStyle is set to yellow highlight:
      //aNode.Select(); 
      aNode.Selected = true;
   }
   else
   {
      aNode.Expanded = false;
      aNode.Selected = false;
   }
}
if (tvwWorkFlow.SelectedNode != null)
   tvwWorkFlow.SelectedNode.Expand();

The result is the TreeView control renders all nodes expanded and the selected node is not highlighted in yellow (until I click on a node).

When I check tvwWorkFlow.SelectedNode after the Treeview control is built, it is null. The Selected property of every node in the TreeView, is null.

Help! Thanks...

The answer was simple:

Move the Expand(), Collapse(), and Select() code to the point after the TreeView has been completely populated as follows:

foreach (WorkFlowTask workFlowTask in WorkFlowTasks)
{
   aNode = new TreeNode(workFlowTask.TaskName, workFlowTask.OrderOfCompletion.ToString());
   CreateNode(aNode); //This method adds nodes to their relative node path

}

// AFTER TREEVIEW IS BUILT:
foreach (Node o in trvWorkFlow.Nodes)
{
   // INSERT CODE HERE TO SELECTIVELY EXPAND, COLLAPSE, OR SELECT NODES.
   o.Expand();
   o.Collapse();
   o.Select();
}