AdmanagerConstrcutor.cs

       /// <summary>
        /// Initialise a new AdMob Ad Overlay. This is a Cross platform method which will run on both Android and iOS.
        /// </summary>
        /// <param name="game">The host game to et the service container from</param>
        /// <param name="location">The location to place the add on the screen</param>
        public AdManager(Game Game, Vector2 location)
        {
            this.Game = Game;

#if __ANDROID__

            //Interstitial Ads
            mInterstitialAd = new InterstitialAd(Game.Activity);
		
	    // Get the Game View
            GameView = (View)Game.Services.GetService(typeof(View));

            // Create the Ad Container
            AdContainer = new LinearLayout(Game.Activity)
            {
                Orientation = Orientation.Horizontal
            };
            AdContainer.SetGravity(GravityFlags.CenterHorizontal | GravityFlags.Bottom);
            AdContainer.SetBackgroundColor(Android.Graphics.Color.Transparent); // Need on some devices, not sure why

            //AdContainer.AddView(RewardedVideoAd);

            // A layout to hold the ad container and game view
            var mainLayout = new FrameLayout(Game.Activity);
            mainLayout.AddView(GameView);
            mainLayout.AddView(AdContainer);
            Game.Activity.SetContentView(mainLayout);

#elif __IOS__
            ViewController = Game.Services.GetService(typeof(UIViewController)) as UIViewController;
            Location = new CGPoint(location.X, location.Y);
#endif
        }