3rd level of hierarchy not expanding

[Rob Conley]

I got the second level to expand by raising a property changed on the parent's ObservableCollection. However, after fetching data for the 3rd level, the second level will not expand after adding a "ItemsOnDemand" collection to the second level. Any idea what I might be missing?

<telerik:RadTreeListView.ChildTableDefinitions>
  <telerik:TreeListViewTableDefinition ItemsSource="{Binding Path=ItemsOnDemand}" />
</telerik:RadTreeListView.ChildTableDefinitions>

[Display(AutoGenerateField = false)]
public ObservableCollection<ISearchDetailFields> ItemsOnDemand
{
  get
  {
    return this._itemsOnDemand;
  }
  set
  {
    this._itemsOnDemand = value;
    this.OnPropertyChanged(new PropertyChangedEventArgs("ItemsOnDemand"));
  }
}

[Maya]

Hello Rob,

I would recommend you to run through this demo for a reference.  

Greetings,
Maya
the Telerik team

[Rob Conley]

Yeah, actually that's why I'm a little confused at the moment as what I have is modeled on that example. I am using RIA entities directly, so hopefully I'll find something there soon that is tripping up the third level of the hierarchy.

[Rob Conley]

For future readers, here's what I found:

To get the 2nd level to expand to the 3rd I had to make the first and second levels collections of the same type. Making collections with the same properties names and types was not good enough; the collection item class had to be the very same class. Note that I was loading on demand and not using an EF association hierarchy (or self-referencing hierarchy).