RadTreeView handles the DropQuery and DragQuery events of the RadDragAndDropManager. However DropInfo and DragInfo are not handled and propagate freely. You can either attach a handler to "Info" events like this:
Or you could add handler to the "Query" events with handeledEvents=true like this:
I would like to recommend you to use some base class in both trees and change the data type. However, you can change the Payload property of the event args in DropQuery event for example. But in this case the originally dragged item will not be removed from the source tree.
In DragInfo event the "DragDropEventArgs.Options.Destination" hold a reference to the destination item. And the DropPosition property of RadTreeViewItem shows you where the node will be dropped (before, after or in).
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