Drag and Drop Nested Items

[Brandon]

Hello all,

I am trying to create a hierarchical tree view (about 3 levels), where the user can drag/drop to re-order, or move items only within the same level, but cannot move items between levels.  Basically I want to maintain a strict hierarchy of items (C's belong only to B's and B's belong only to A's).

I have tried using a hierarchical data template for my view model (which implements INotifyPropertyChanged) but can only reorder the top level nodes and cannot reorder the child nodes.


Thanks for any help!

[Petar Mladenov]

Hi Brandon,

In order to reorder RadTreeViewItems in databinding scenarios, you have to make sure the root ViewModel Collection and the Child ViewModel collections are ObservableCollection. Usually the ViewModels structure you have to use is:

MainViewModel
{
  public ObservableCollection<DataItem> RootCollection;
}

DataItem
{
 public string Header
 public ObservableCollection<DataItem> Children;
}

Please let us know if this helped you or not.

Regards,
Petar Mladenov
the Telerik team

[Brandon]

I am using an ObservableCollection in my view model, but it is still behaving as described previously.

[Petar Mladenov]

Hi Brandon,

 I think this example could help you. You can examine it's code which shows how to prevent certain drag/drop operation when a particular condition is true/false. Same technique could be used in WPF.

Kind regards,
Petar Mladenov
the Telerik team