The line of code below is in my NodeClicked method and in the debugger it displays the key correctly. But where do I get the "5" (or whatever node number) from? I thought it was INDEX, but that does not return anything.

The TreeView control has a single SelectedItem property that contains an object reference to the currently selected Node. It is the Nodes collection and the individual Node objects that have the properties required to navigate the tree. You can access an individual Node in the collection using either its Key or its Index like this:

Thisform.oTree.Nodes( Key ) or Thisform.oTree.Nodes( Index )

However, the value of its Index is entirely dependent on the order in which the Node is added to the TreeView so it is only useful in those instances where you need to iterate through all the children in the Nodes collection of a specific Node.