Designer shows the super class name instead of the subclass name on control previews

When a subclass of a built-in control is placed on a window, the designer preview labels it with the super class name instead of the subclass name. For example, a Canvas subclass called MyClass placed on Window1 shows the italic placeholder text "Canvas" inside its rectangle. A subclass instance and a plain built-in control therefore look identical on the designer surface, and the only text shown is the wrong name. The preview should keep rendering the built-in control's appearance but label the placeholder with the actual class name.