title: Admob not displaying on Android Platform
body: <p>I'm having trouble displaying ad inside my android app in xamarin form, in iOS everything seems to work fine but on Android I'm just getting a blank view here the two screenshot :
  <a href="https://i.stack.imgur.com/soWuf.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/soWuf.jpg" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/Zkup5.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Zkup5.jpg" alt="enter image description here"></a></p>
  
  <p>here is my android manifest</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionName="2.0" package="it.HangoverApp.Hangover" android:installLocation="auto" android:versionCode="1"&gt;
      &lt;uses-sdk android:minSdkVersion="26" android:targetSdkVersion="27" /&gt;
      &lt;uses-permission android:name="android.permission.CAMERA" /&gt;
      &lt;uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /&gt;
      &lt;uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /&gt;
      &lt;uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /&gt;
      &lt;uses-permission android:name="android.permission.INTERNET" /&gt;
      &lt;uses-permission android:name="android.permission.ACCESS_LOCATION_EXTRA_COMMANDS" /&gt;
      &lt;uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" /&gt;
      &lt;uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /&gt;
      &lt;uses-permission android:name="android.permission.ACCESS_WIFI_STATE" /&gt;
      &lt;activity android:name="com.google.android.gms.ads.AdActivity" android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize" android:theme="@android:style/Theme.Translucent" /&gt;
      &lt;application android:label="Hangover.Android" android:name="android.support.multidex.MultiDexApplication"&gt;
          &lt;receiver android:name="com.google.firebase.iid.FirebaseInstanceIdInternalReceiver" android:exported="false" /&gt;
          &lt;receiver android:name="com.google.firebase.iid.FirebaseInstanceIdReceiver" android:exported="true" android:permission="com.google.android.c2dm.permission.SEND"&gt;
              &lt;intent-filter&gt;
                  &lt;action android:name="com.google.android.c2dm.intent.RECEIVE" /&gt;
                  &lt;action android:name="com.google.android.c2dm.intent.REGISTRATION" /&gt;
                  &lt;category android:name="${applicationId}" /&gt;
              &lt;/intent-filter&gt;
          &lt;/receiver&gt;
          &lt;provider android:name="android.support.v4.content.FileProvider" android:authorities="${applicationId}.fileprovider" android:exported="false" android:grantUriPermissions="true"&gt;
              &lt;meta-data android:name="android.support.FILE_PROVIDER_PATHS" android:resource="@xml/file_paths"&gt;&lt;/meta-data&gt;
          &lt;/provider&gt;
          &lt;meta-data android:name="com.google.android.gms.ads.APPLICATION_ID" android:value="ca-app-pub-3926326346203258~3222437594" /&gt;
          &lt;meta-data android:name="com.google.android.maps.v2.API_KEY" android:value="AIzaSyDhDVDVl6Z1vO9CwAL9xx2ypjMw-QhZAHw" /&gt;
          &lt;meta-data android:name="com.google.android.gms.version" android:value="@integer/google_play_services_version" /&gt;
          &lt;provider android:authorities="com.facebook.app.FacebookContentProvider614171362072741" android:name="com.facebook.FacebookContentProvider" android:exported="true" /&gt;
          &lt;meta-data android:name="com.facebook.sdk.ApplicationId" android:value="@string/facebook_app_id" /&gt;
          &lt;activity android:name="com.facebook.FacebookActivity" android:configChanges="keyboard|keyboardHidden|screenLayout|screenSize|orientation" android:label="@string/facebook_app_name" /&gt;
          &lt;activity android:name="com.facebook.CustomTabActivity" android:exported="true"&gt;
              &lt;intent-filter&gt;
                  &lt;action android:name="android.intent.action.VIEW" /&gt;
                  &lt;category android:name="android.intent.category.DEFAULT" /&gt;
                  &lt;category android:name="android.intent.category.BROWSABLE" /&gt;
                  &lt;data android:scheme="@string/fb_login_protocol_scheme" /&gt;
              &lt;/intent-filter&gt;
          &lt;/activity&gt;
      &lt;/application&gt;
  &lt;/manifest&gt;
  </code></pre>
  
  <p>Here is the code of the cell:</p>
  
  <pre><code>xmlns:cs="clr-namespace:Hangover.GUIPersonalizzata;assembly=Hangover" 
        &lt;Frame  HasShadow="True" CornerRadius="15" IsVisible = "{Binding shouldDisplayAd}"
                      HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" HeightRequest = "255"
                      Margin="5,3,5,1" BackgroundColor="White" Padding="0" IsClippedToBounds="True"&gt;
  
                      &lt;cs:AdMobView Size="MediumRectangle" VerticalOptions="EndAndExpand"/&gt;  
  
                 &lt;/Frame&gt;
  </code></pre>
  
  <p>Here is the AdMobView:</p>
  
  <pre><code>using System;
  using Xamarin.Forms;
  
  namespace Hangover.GUIPersonalizzata
  {
      ///Custom renderer per la pubblicità
      public class AdMobView : View
      {
          public enum Sizes { Standardbanner, LargeBanner, MediumRectangle, FullBanner, Leaderboard, SmartBannerPortrait }
          public Sizes Size { get; set; }
  
          public AdMobView()
          {
              this.BackgroundColor = Color.Black;
          }
      }
  }
  </code></pre>
  
  <p>And here the custom renderer:</p>
  
  <pre><code>using Android.Content;
  using Android.Gms.Ads;
  using Hangover.Droid.CustomRenderer;
  using Hangover.GUIPersonalizzata;
  using Xamarin.Forms;
  using Xamarin.Forms.Platform.Android;
  
  [assembly: ExportRenderer(typeof(AdMobView), typeof(AdMobViewRenderer))]
  namespace Hangover.Droid.CustomRenderer
  {
      public class AdMobViewRenderer : ViewRenderer
      {
          Context context;
  
          public AdMobViewRenderer(Context _context) : base(_context)
          {
              context = _context;
          }
          protected override void OnElementChanged(ElementChangedEventArgs&lt;View&gt; e)
          {
              base.OnElementChanged(e);
              if (e.OldElement == null)
              {
                  var adView = new AdView(Context);
                  switch ((Element as AdMobView).Size)
                  {
                      case AdMobView.Sizes.Standardbanner:
                          adView.AdSize = AdSize.Banner;
                          break;
                      case AdMobView.Sizes.LargeBanner:
                          adView.AdSize = AdSize.LargeBanner;
                          break;
                      case AdMobView.Sizes.MediumRectangle:
                          adView.AdSize = AdSize.MediumRectangle;
                          break;
                      case AdMobView.Sizes.FullBanner:
                          adView.AdSize = AdSize.FullBanner;
                          break;
                      case AdMobView.Sizes.Leaderboard:
                          adView.AdSize = AdSize.Leaderboard;
                          break;
                      case AdMobView.Sizes.SmartBannerPortrait:
                          adView.AdSize = AdSize.SmartBanner;
                          break;
                      default:
                          adView.AdSize = AdSize.Banner;
                          break;
                  }
  
                  adView.AdUnitId = App.getBannerId();
                  var requestbuilder = new AdRequest.Builder();
                  adView.LoadAd(requestbuilder.Build());
                  SetNativeControl(adView);
              }
          }
  
      }
  }
  </code></pre>
  
  <p>Here the ids:</p>
  
  <pre><code>public static String getBannerId()
          {
              if (TESTMODE)
                  return "ca-app-pub-3940256099942544/2934735716";
              if (Device.RuntimePlatform == Device.iOS)
                  return "ca-app-pub-3926326346203258/2224942897";
              if (Device.RuntimePlatform == Device.Android)
                  return "ca-app-pub-3926326346203258/8267251849";
              return "";
          }
          public static String getAppAddId()
          {
              if (Device.RuntimePlatform == Device.iOS)
                  return "ca-app-pub-3926326346203258~6439520076";
              if (Device.RuntimePlatform == Device.Android)
                  return "ca-app-pub-3926326346203258~3222437594";
              return "";
          }
  </code></pre>
  
  <p>Here is the log output from the ad:</p>
  
  <p>[Ads] Use AdRequest.Builder.addTestDevice("23A6FE4B4656BDF0239595258F8C1876") to get test ads on this device.
  [DynamitePackage] Instantiating com.google.android.gms.ads.ChimeraAdManagerCreatorImpl
  [Ads] Use </p>
  
  <pre><code>AdRequest.Builder.addTestDevice("23A6FE4B4656BDF0239595258F8C1876") to get test ads on this device.
  [Ads] Not retrying to fetch app settings
  [Ads] Ad failed to load : 3
  [Ads] Ad failed to load : 3
  </code></pre>
  
  <p>Even if the app is in release mode, any ideas?</p>