private async Task ShowBanner()
        {
            try
            {
                bannerLayout.Visibility = ViewStates.Visible;

                if (revmobBanner != null)
                {
                    revmobBanner.Show();
                    return;
                }

                var revMob = await RevMobHelper.TryGetAdMobSessionAsync(startSessionListener);

                if (revMob == null)
                {
                    HideBanner();
                    return;
                }

                revmobBanner = revMob.CreateBanner(this, "", showBannerAdListener);
                revmobBanner.SetAutoShow(true);

                ViewGroup view = FindViewById <ViewGroup>(Resource.Id.webViewContainer_banner);

                view.RemoveAllViews();
                view.AddView(revmobBanner);
            }
            catch { }
        }
        public void ShowBannerAd()
        {
            if (null != _bannerContainer || null != revmobBanner)
            {
                //There is already a banner ad displayed
                HideBannerAd();
            }

            if (RevMob.Session() != null)
            {
                revmobBanner = RevMob.Session().CreateBanner(Game.Activity, "", bannerListener);
                revmobBanner.SetAutoShow(true);

                // A container to show the add at the bottom of the page
                _bannerContainer             = new LinearLayout(Game.Activity);
                _bannerContainer.Orientation = Orientation.Horizontal;
                _bannerContainer.SetGravity(GravityFlags.CenterHorizontal | GravityFlags.Bottom);
                _bannerContainer.SetBackgroundColor(Color.Transparent);                 // Need on some devices, not sure why

                _rootLayout.AddView(_bannerContainer);
                _bannerContainer.AddView(revmobBanner);
            }
        }