treeviewitem not expanding when new item dropped on

[Brian]

I have a list box that drops an item onto a treeView.   The TreeView is bound to a List<> and has a two level template.  The Item is dropped on the top level items and need the item to expand when the new item is dropped on it.

private void OnDropInfo(object sender, DragDropEventArgs e)
       {

               if (e.Options.Status == DragStatus.DropComplete)
               {

                   ListBoxItem item = e.Options.Source as ListBoxItem;
                   DeviceApp payload = item.Content as DeviceApp;
                   freeApps.Remove(payload);
                   appList.UnselectAll();
                   appList.ItemsSource = freeApps;
                   stationTree.ItemsSource = stations;
                   appList.Items.Refresh();
                   stationTree.Items.Refresh();

               }


       }

The listBox is the source and i have added some clunky Refresh() to get both ItemsSources to update and show the changes.  I know i am doing this wrong, but the tree branch still does not expand on drop.

Any help would be great! 
Thanks,
Brian

[Tina Stancheva]

Hello Brian,

The RadTreeView has a built-in drag/drop logic that can be used out-of-the-box in order to implement your scenario. You can examine this demo demonstrating how to drag items from ListBox to the RadTreeView and vice verca (the demo is for Silverlight, however you can implement it in WPF as well). You can also have a look at this help article for more info.

Also, please keep in mind that in databound scenarios, when you want the changes applied to the ItemsSource collection of the RadTreeView to be reflected by the control, then you need to bind it to a collection that implements the INotifyCollectionChanged interface, for example an ObservableCollection.

I hope that info helps.

All the best,
Tina Stancheva
the Telerik team