title: Implement Prism in existing Xamarin.Forms Shared Application
body: <p>I would like to know of there is a valid way to implement Prism in a existing Xamarin.Forms Shared project. I'm sure others would also like to know if they can profit from what Prism has to offer without having to convert their existing project to a PCL project. All existing examples I've found show a PCL project(probably for a good reason).</p>
  
  <p>To try implementing Prism in my project I installed the Prims.Unity.Forms nuget to each platform project. 
  I tried to inherit from PrismApplication: </p>
  
  <pre><code>public partial class App : PrismApplication 
  { }
  </code></pre>
  
  <p>But, this does not work. The app class does not allow me to inherit from a different base class.</p>
  
  <p>Adding the following lines to my android project did not help:</p>
  
  <pre><code>protected override void OnCreate(Bundle bundle)
  {      
     LoadApplication(new App(new AndroidInitializer()));
  }
  
  public class AndroidInitializer : IPlatformInitializer
  {
     public void RegisterTypes(IUnityContainer container)
     { }
  }
  </code></pre>
  
  <p>Perhaps I am missing something or trying something that structurally is not possible.</p>