namespace DroneMusic.Droid {
    [Activity(Label = "App", Icon = "@drawable/icon", Theme = "@style/MainTheme",
        ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
    public class MainActivity : Xamarin.Forms.Platform.Android.FormsAppCompatActivity {
        protected override void OnCreate(Bundle bundle) {
            TabLayoutResource = Resource.Layout.Tabbar;
            ToolbarResource = Resource.Layout.Toolbar;
            base.OnCreate(bundle);
            UserDialogs.Init(this);
            Forms.Init(this, bundle);
            var platformVkAuthorizer = fun(() => {
                VKSdk.Login((Activity)Forms.Context);
                //вот тут получить результат колбэка
                return Left<VkError, VkToken>(new VkError("hui"));
            });
            LoadApplication(new DroneMusicApp(platformVkAuthorizer));
        }
        protected override void OnActivityResult(int requestCode, Result resultCode, Intent data) {
            if (!VKSdk.OnActivityResult(requestCode, (int)resultCode, data, new VkCallback())) {
                base.OnActivityResult(requestCode, resultCode, data);
            }
        }
        private class VkCallback : Object, IVKCallback {
            public void OnError(VKError p0) {
                throw new NotImplementedException();
                //вот тут бросить результат колбэка
            }

            public void OnResult(Object p0) {
                throw new NotImplementedException();
                //вот тут бросить результат колбэка
            }
        }
    }
}