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gong-wpf-dragdrop - issue #49

The Dropped function from IDragSource is called on the target and not the Source


Posted on Nov 15, 2012 by Swift Kangaroo

What steps will reproduce the problem? 1. Create a ViewModel class A and implement IDragSource 2. Create a ViewModel class B and implement IDropTarget 3. Create two ListBox (named LBA and LBB). 5. Set the datacontext of LBA to a viewModel instance of type A. 6. Set the datacontext of LBB to a viewmodel instance of type B 7. Set the IsDragSource and DragHandler to LBA 8. Set the IsDropTarget and DropHandler to LBB 9. Try to move items from LBA to LBB

What is the expected output? What do you see instead? I would like the Dropped function on my view model A to be called when a drop occurs Instead of the one ine the DefaultDragHandler

What version of the product are you using? On what operating system? Last one, Windows 7

Please provide any additional information below.

Looking at the code, it seems that the issue came from file: DragDrop.cs function: static void DropTarget_PreviewDrop(object sender, DragEventArgs e) Line: IDragSource dragHandler = GetDragHandler((UIElement)sender) ?? DefaultDragHandler;

We are getting the DragSource of the sender uiElement which is the target one (i.e. LBB)

I fixed it by replacing the line with this one: IDragSource dragHandler = GetDragHandler(_DragInfo.VisualSource) ?? DefaultDragHandler;

Comment #1

Posted on Nov 20, 2012 by Swift Kangaroo

Note: My fix is not working when you drop something from an external application

Status: New

Labels:
Type-Defect Priority-Medium