OK. I finally managed to create the sample ATL called Polygon from the ATL Tutorial on MSDN using the Visual Studio 2010 Beta 1. The problems I mention in the previous post remain; I simply hand-coded the text that the ATL wizard failed to create (well, maybe simply is not appropriate here). Anyway, back to interop. We have two scenarios to examine: WPF using COM objects and Windows Forms User Controls Windows Forms using WPF controls Let’s start with the first. In the rest of this post I will describe...