title: Extending a WPF window in codebehind between projects
body: <p>I have a XAML/cs class (EditorWindow) that derives from Window and implements some special functions.
  I also have a subclass in just a .cs file that derives from EditorWindow (public class DetailedEditorWindow:EditorWindow).</p>
  
  <p>If both of these are in the same project, I can open the DetailedEditorWindow just fine (it makes no difference if they are in different namespaces), but if I move DetailedEditorWindow to another project which references EditorWindow, I get a resource missing SystemException - saying it misses the EditorWindow.xaml. </p>
  
  <p>Why is this and how can I fix this error?</p>
  
  <p>Thank you in advance,
  JasonX</p>