In this case one possible workaround would be the approach shown in the attached project from my last response. You can simply subscribe for the RadTreeView OnClientNodeDropping
client-side event and cancel the drop action by default but store in some global variable or hidden filed the node object prepared for delete.That way you will be able to delete that node explicitly from the callback function of the RadConfirm
dialog box if the user has selected "Ok". If he has selected "Cancel" you don't need to do anything since you have already cancelled the node dropping.
If you want to delete the node object on the server - you can simply execute an Ajax request using the RadAjaxManager and access the RadTreeView object on the server and perform the delete process. Here you may find here
more information about explicit AJAX requests to the server from the client.
Hope that this will be helpful.
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