The MindFusion Forums - How can you tell when a drag is canceled?

(UTC)

The MindFusion Forums › Flow Diagramming Components › WPF › How can you tell when a drag is canceled?

(Moderator: Slavcho)

‹ Previous Topic | Next Topic ›

Pages: 1

How can you tell when a drag is canceled? (Read 1791 times)

David Cater YaBB Newbies Offline I Love MindFusion! Posts: 12 Joined: May 12^th, 2012	How can you tell when a drag is canceled? May 16^th, 2012 at 5:38pm	Print Post
	I have a NodeListView and a Diagram. I am dragging from the NodeListView to the Diagram. I am trying to take some actions when a drag starts and when it finishes for any reason (drop or canceled drag). I catch the DragEntered event on the Diagram object to determine when the drag "starts" (although I have to be careful, because DragEntered can occur multiple times). Is there any way to track the status of the drag to find out when it has finished? Thanks, David


	IP Logged

Stoyo God Member Offline MindFusion support Posts: 13230 Joined: Jul 20^th, 2005	Re: How can you tell when a drag is canceled? Reply #1 - May 16^th, 2012 at 5:53pm	Print Post
	Hi, I think drag and drop from the NodeListView is always accepted by default, and you should get both Drop and NodeCreated events raised when the node is dropped. That should make the DragLeave event the only way to cancel. I hope that helps, Stoyan


	IP Logged

David Cater YaBB Newbies Offline I Love MindFusion! Posts: 12 Joined: May 12^th, 2012	Re: How can you tell when a drag is canceled? Reply #2 - May 16^th, 2012 at 7:43pm	Print Post
	The problem with that is that DragLeave will occur on the NodeListView when the mouse leaves the boundaries of the NodeListView, not when the drag is done. And if you bring up a user interface over the diagram when it is dragged over (which is what I'm doing), the diagram will also get DragLeave. In both of those cases, the drag is still going on. I'll look at the source code for the drag and consider adding a static event of some sort that the Mindfusion code can raise when the drag is done. That's what I've done with similar drag/drop code of my own in the past. Then my code can hook that event (and a similar "DragStarted" event). D.


	IP Logged

Stoyo God Member Offline MindFusion support Posts: 13230 Joined: Jul 20^th, 2005	Re: How can you tell when a drag is canceled? Reply #3 - May 17^th, 2012 at 6:00am	Print Post
	Now I see what do you mean. The drag is over when the DragDrop.DoDragDrop returns, but apparently there isn't any standard WPF event raised to indicate that. If you have the code, you can add a custom NodeListView event raised from OnPreviewMouseMove after the DragDrop.DoDragDrop(...) line. You will know the outcome of the drag operation from the DragDropEffect enum value returned by DoDragDrop - it should be either None or Copy. I hope that helps, Stoyan


	IP Logged

Pages: 1

‹ Previous Topic | Next Topic ›