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How to get underlying object... always null

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This is a migrated thread and some comments may be shown as answers.
Nigel Shaw
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Nigel Shaw asked on 06 Mar 2010, 04:44 PM
I'm trying to get the underlying object that's bound to a dropped item in a drag-drop operation. In my case the underlying object is of type Model.Topic.

I use the following code:

private void RadTreeView_DragEnded(object sender, Telerik.Windows.Controls.RadTreeViewDragEndedEventArgs e)  
        {  
            object droppedTopics = e.DraggedItems;  
              
            object targetDropItem = e.TargetDropItem;  
            Model.Topic targetTopic = targetDropItem as Model.Topic;  
 
            foreach (object droppedTopic in e.DraggedItems as Collection<object>)  
            {  
                Model.Topic sourceTopic = droppedTopic as Model.Topic;  
                targetTopic.ParentTopicId = sourceTopic.ID;  
            }  
        }  
 

The problem is that after the following line, targetTopic is always null.

Model.Topic targetTopic = targetDropItem as Model.Topic; 

The question is, what is the correct way to get the underlying object that is bound to a dragged/dropped item?

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Tina Stancheva
Telerik team
answered on 10 Mar 2010, 05:47 PM
Hi Nigel Shaw,

The targetTopic is null because e.TargetDropItem is the dynamically generated container for your business object. Therefore you need to cast it to the type of the container (RadTreeViewItem) like this:
     RadTreeViewItem container = e.TargetDropItem as RadTreeViewItem;
Afterwards, you can access the business object itself via the container.Item property:
    Model.Topic targetTopic = container.Item as Model.Topic;

Regards,
Tina Stancheva
the Telerik team

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Nigel Shaw
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Tina Stancheva
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