Hello Anders.

Is there anyone how can help me to understand how you can catch which node is expanded when a treeview control is expanded?

I addition to what the others have said, you may want to take a look at the SelectedItem property of the TreeView.

This is an object reference to the selected node (in other words, the node that was expanded last < s > )

loNode = oTree.SelectedItem
?loNode.Text
?loNode.Key