Offline Map using MapBox with Xamarin.Forms(Shared).Android

I am working to create a Moblie APP for iOS and Android using Xamarin.Forms(Shared) project. Using MAPBox SDK and some GeoJSON coordinates, I have created a sample which can show the Polyline and Polygon.
I am looking for some sample code for Xamarin.Forms(Shared).Android which can provide the feature of offline maps and using that Offline map and GeoJSON data, I can draw the Polyline and Polygon.
Can you provide some sample code which can fulfill our requirement?