title: NavigationWindow - Where is it?
body: <p>My WPF application is becoming a real pain. I have created a Window and would like to load another page when I click on a button. I assumed this would be straightforward, but it doesn't seem to be. I manage to load the other page by using <code>this.content = new UserPage()</code>. However, from this UserPage, I can't get back to my main window. I can't use <code>this.content</code> because the window can't be a child. </p>
  
  <p>Therefore, I searched around and found out I should be using NavigationService to make things a lot easier. I tried to use <code>NavigationService.GetNavigationService(this)</code> but this didn't work as it always returned null. I figured it's because my main window is derived from <code>Window</code> and not <code>NavigationWindow</code>. Is there a way to convert my Window into a NavigationWindow without starting the project again? Whenever I create a new file, there's no NavigationWindow template - only Window, Page, User Control etc...</p>
  
  <p>I tried manually replacing the XAML with NavigationWindow and it ran fine, but the NavigationService method still returned null. There was a bar at the top as well with back and forward arrow (both disabled), but I don't really need this. I would just like to use the <code>Navigate()</code> method so that I can easily switch between pages.
  Any ideas on what I can do?</p>
  
  <p>Thanks for any help, this is driving me nuts! :)</p>