This is from the documentation for "User Interface Compositions" in the composite application library:
The composite application library has the following region adapters: ContentControlRegionAdapter SelectorRegionAdapter and ItemsControlRegionAdapter . These adapters are designed to adapt controls derived from ContentControl , Selector and ItemsControl , respectively. There is an additional adapter, TabControlRegionAdapter , used in Silverlight because the Tab control does not derive from Selector , as in WPF.
So, the game here in a nutshell is that these adapters work for any control that comes from these supported containers. For example, a TabControl inherits from Selector .
This is obviously not the limit. If you have your own control that does not inherit from one of these controls, you can implement your own region adapter to support this control.
Hope this helps, Anderson
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