What Drag and Drop library to use?

[Clint Singer]

Hi,

I am a little confused as to which library I should be using for my brand new drag and drop items.  There seems to be three options, RadDragAndDropManager, DragDropManager and some drag and drop behaviors.

I began using the DragDropManager because I was under the impression that RadDragAndDropManager was being deprecated.  Yet, today on XAMLflix there is a video covering its usage which I find odd for something that is being deprectated.

Originally I was going to be using RadDragAndDrop manager because it looked more capable but chose to not use it due to it's end of life status. So, I chose DragDropManager instead because it looked like it gave me a custom drag and drop experience as I was in need of doing more than just dragging between listboxes or treeviews as demonstrated in the demos.  Unfortunately I have also had some problem in figuring out how to make a custom drag visual that changes as I move over the custom drag targets. The documentation hasn't been clear how to do this.

It seems the pattern is that the source needs to determine who it can drop onto but to me it would make more sense if the target could state that it is willing to accept the item and change the drag visual accordingly.

Perhaps this is the way it could work but by just using the DragDropManager and the documentation, it isn't obvious how this works.

Cheers,
Clint

[Nick]

Hello Clint,

You are absolutely, the documentation lacks a lot of details on how to achieve certain goals, and we are doing our best to fill the gaps and provide more detailed information on cases of this nature. 

The official statement is that the RadDragAndDropManager will be marked as Obsolete as of Q2 2012. And DraggDropManager and the behaviors that are built on it are the official drag drop mechanism. We are currently updating all our examples to use the new mechanism.

As for the issue at hand, the most effective way to achieve the goal you are looking for is to create a ViewModel that is to be used as a Content for the DragVisual which should have a template that reacts to that ViewModel. You can then keep a reference to this object and update it when needed. With the release of Q2 2012, there will be some updates in the Data API in the DragDropManager that will allow you to keep the all the details you need in the Drag payload, not just the dragged data, so it will be easier to implement your scenario. 

Hope this helps! 

All the best,
Nik
the Telerik team