WPF HiercharchicalDataTemplate.DataType: How to react on interfaces?

Question

Problem

I\'ve got a collection of IThings and I\'d like to create a HierarchicalDataTemplate for a TreeView. The straightfor

Answer 1

Another alternative (similar to jing's solution): If you only have one type of item, you can set the ItemTemplate directly. Then you don't need to set a key or a datatype.

In your ViewModel:

public ObservableCollection Thingies { get; private set; }

In the View: