protected override void OnCreate(Bundle savedInstanceState) { base.OnCreate(savedInstanceState); Xamarin.Essentials.Platform.Init(this, savedInstanceState); SetContentView(Resource.Layout.activity_main); FManager = FragmentManager; BottomNavigationView navigation = FindViewById <BottomNavigationView>(Resource.Id.navigation); navigation.SetOnNavigationItemSelectedListener(this); OnNavigationItemSelected(navigation.Menu.GetItem(0)); sMessageEngine = Nearby.GetMessageEngine(this); RequestPermissions(); sMessageEngine.RegisterStatusCallback(new MyStatusCallback()).AddOnCompleteListener(new TaskListener(this, " RegisterStatusCallback")).AddOnFailureListener(new TaskListener(this, " RegisterStatusCallback")); }