In the fh-xamarin-sdk push APIs we have a interface IPush which is accessed as follows

ServiceFinder.Resolve<IPush>().Register(HandleNotification); 

ServiceFinder is responsible for determining which implementation is currently linked in the app. What this means is that when you build xamarin forms for iOS you depend on the iOS implementations in your build configuration and likewise for Android. This is probably easiest if you have an Android and iOS forms project which bootstrap the whole thing.

Links

• IPush Shared code Network
• IPush Shared code Network Push
• Android IPush impl
• Ios push impl

Example Xamarin apps