TreeViewDragCue via DragDropManager.

[Pavel]

I'm dragging item from TreeView to TreeListView and want to update TreeViewDragCue dynamicly to set its' IsDropPossible property. 
How can I get an object of it?
Thanks,
Pavel.

[Nick]

Hi Pavel,

You can save a reference to the Visual in the DragInitialize event and use it later on for the Drag operation.

Hope this helps! 

Regards,
Nik
the Telerik team

[Pavel]

But where can I get it? DragVisual is null. 
Thanks,
Pavel.

[Pavel R. Pavlov]

Hello Pavel,

When using our DragDropManager you can subscribe to the DragInitialize event. In its event handler you are allowed to set a DataTemplate (defined in your XAML) to the e.DragVisual property. When setting it you can save a reference to it like this:

private var myDragVisual;
private void OnDragInitialize(object sender, DragInitializeEventArgs
{
    ...
    myDragVisual = new ContentControl { ContentTemplate = this.Resources["MyDragCueTemplate"] as DataTemplate };
    e.DragVisual = myDragvisual;
    ...
}

By doing so you will be able to modify your visual later on.

For more information you can refer to our documentation or our online demonstration project.

Regards,
Pavel R. Pavlov
the Telerik team

[Pavel]

Ok, you right, but I asked about how can I get Cue that automaticly setted by treelistview? 
Exactly that cue that named as "TreeListViewDragCue" and placed in Telerik.Windows.Controls namespace.
Did you read it? 
Thanks, 
Pavel.

[Nick]

Hi Pavel,

Do you get null values for the DragVisual when you start the drag from both TreeList and TreeView? 

Looking forward to hearing from you! 

All the best,
Nik
the Telerik team

[Pavel]

Hello Nik,
I got null in both cases in both controls. 
Even I do reordering in TreeListView. Visual feedback from drag'n'drop is presented, but still null in DragVisual. 
Thanks, 
Pavel.

[Nick]

Hello Pavel,

I tested your scenario locally and get the same behavior. May I ask you to subscribe to the DragSterted events and see if you get null value there too? 

Looking forward to hearing from you! 

Kind regards,
Nik
the Telerik team

[Pavel]

I have no idea where can I find this event. 
I use DragDropManager.
Thanks,
Pavel.

[Nick]

Hi Pavel,

Unfortunately it turns out you cannot get the cue at the moment. We are going to investigate further and provide a fix as soon as possible. 

As to updating states of the TreeListViewDragCue, we have fixed the problem regarding the cue not updating its states according to the drag effects, so now you can just set the DragEffects to none, for example, and the cue will reflect that change with the drop not allowed sign. The fix will be available with our next internal build.

Hope this helps! 

Regards,
Nik
the Telerik team