TreeView.BeforeDragOverHighlight Event
This event is fired when a node is dragged over before the highlight change will be drawn. So you can use this one for example to change icons based on the highlight state.

BeforeDragOverHighlight(
node
as TreeViewNode,
willBeHilited
as Boolean)
Parameters
- node
- The node to be highlighted or de-highlighted.
- willBeHilited
- True if the node is getting highlighted, false if it is getting de-highlighted.
Remarks
See Also
TreeView Control