After reading about Visual Studio 11's Portable Libraries, I tried putting my common library for WPF into one that targets both .NET 4 and Metro-style UIs. I can't seem to figure out how to get the compiler to recognize certain classes, even after adding additional references while ignoring the warning that "The project will be retargeted to the .NET portable subset". The ones that puzzle me the most are the classes "Control" and "ItemsControl" since I know they exist in both WPF and Metro UIs. Why can't the compiler find these classes?
The portable libraries are for non-GUI type classes. Mostly business logic.