Remove the "not allowed" icon on drag

[Jacob]

Hello Telerik,

 

I am implementing a feature which consists of a list of user controls that can be dragged to dock panels.

however, as you can see in the attached picture, there is this red "not allowed"-like icon showing, although the functionality works fine.

I just need to remove that icon. is there a way to do so?

 

Thank you

[Martin Ivanov]

Hi Jacob,

To hide the icon you can change the DropAction of the drag payload of the treeview. To do this you can subscribe the drop target to the DragDropManager.DragOver event. Then get the TreeViewDragDropOptions provided by the event arguments and set their DropAction to a value different than None.

For example:

DragDropManager.AddDragOverHandler(this.dropTargetControl, OnDropTargetDragOver, true);

private void OnDropTargetDragOver(object sender, Telerik.Windows.DragDrop.DragEventArgs e)
{
    var options = DragDropPayloadManager.GetDataFromObject(e.Data, TreeViewDragDropOptions.Key) as TreeViewDragDropOptions;
    if (options != null)
    {
        options.DropAction = DropAction.Copy;
        options.UpdateDragVisual();
    }
}

You can also use the DragEnter and DragLeave of DragDropManager instead of DragOver. Check the attached project for a sample implementation.

Alternatively you can get the DragVisual (TreeViewDragVisual) element from the TreeViewDragDropOptions and set its IsDropPossible to True.

If you want to completely hide the tooltip that shows the icon you can get the DragVisual 

var dragVisual = (TreeViewDragVisual)options.DragVisual;
dragVisual.DragTooltipVisibility = Visibility.Collapsed;

Regards,
Martin Ivanov
Progress Telerik

[Jacob]

Thank you Martin. Your solution works perfectly.