UWP Basics - Navigation

Learn how to use existing NavigationService by using Prism for Xamarin Forms' platform and how to implement your own. We think about NavigationService with MVVM applications where we want to perform page navigation from within the ViewModel instead of the View, to ensure testability and extensibility.
How could you combine your last video, dependency injection with xamarin forms with prism ?
I'm trying to inject other dependencies, with iNavigationService but always get error.
//It doesn't work, how it's the correct way?
public MainPageViewModel(INavigationService navigationService, IMainService mainService)
{
_navigationService = navigationService;
_mainService = mainService;
}
@HoussemDellai Thanks for the great video. Keep up the good work.
@steven: You have to register your types with the container in the RegisterTypes method in the App.cs.
Example: Container.RegisterType<IMyService, MyService>();
You might consider making them a singleton if possible.
@Brian Lagunas thank you for the answer :) I just saw it now !