title: WPF-App Embedd WPF window/control from other AppDomain
body: <p>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.</p>
  
  <p>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.</p>
  
  <p>Now the <strong>problem</strong> 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).</p>
  
  <p>As far as I searched up to now it should be possible 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 <em>Pipeline</em>, <em>Contract</em> and <em>FrameworkElementAdapter</em>. I am somewhat stuck and any more specific hints will be appreciated!</p>