title: WPF - access to resources in design time when App.xaml's Build Action = Page
body: <p>I changed the build action of my App.xaml to "Page" so I could handle a splash screen and make sure my application run as a single instance only (having my own entry point).
  It works fine in run-time but in design-time the application cannot see the my resources anymore. Resources are in separate xaml files located in the same project.
  How can I make my app see the resources in design-time again?</p>
  
  <p>Thanks</p>