WPF-App Embedd WPF window/control from other AppDomain

I have an assembly which generates a Form (it is a client-software). I can build an app getting and starting (Show) that form without any problem. But I cannot start that Form twice because the assembly does not provide a clean capsuled solution. Every second start it would crash because several things will not initialize successful a second time. Unfortunately that assembly cannot be modified.

Now I have put that in a seperate AppDomain to be able to unload that assembly. This works fine and the hosting application can now start that Form multiple times.

Now the problem is: I have a WPF-app which should not show that assembly's Form, it should contain it in one of its own windows. The WinForms Form of the assembly is already in a WindowsFormHost and WPF-Window (with AssemblyAppDomain). But I cannot assign the WPF-Window as Content of one of the main WPF-app-windows. It is in the AssemblyAppDomain AppDomain (and object space is not shared with that).

As far as I searched up to now it should be pos开发者_开发技巧sible to establish a connection between two WPF windows in different AppDomains because that is kind of the way System.AddIn works. Should work with a Pipeline, Contract and FrameworkElementAdapter. I am somewhat stuck and any more specific hints will be appreciated!

Have you checked the docs about WPF addins? Also check out this example.