正如标题所述，我正在尝试将admob广告应用到我的应用程序中，但是当我使用测试广告时，他们没有显示。
启动画面活动：
base.OnCreate(savedInstanceState);
//Ensures that the SDK has been initialized with our publisher app ID
var id = "xxxx";
Android.Gms.Ads.MobileAds.Initialize(ApplicationContext, id);
//Starts main part of app
StartActivity(new Intent(Application.Context, typeof(MainActivity)));
然后转到主要活动，其中包含我的应用程序的主要部分：
base.OnCreate(savedInstanceState);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.activity_main);
//sets up the the toolbar and tabs
SetSupportActionBar(FindViewById(Resource.Id.maintoolbar));
SupportActionBar.Title = "Rower Stuff";
TabLayout tabs = FindViewById(Resource.Id.tabs);
ViewPager viewPager = FindViewById(Resource.Id.viewpager);
SetUpViewPager(viewPager);
tabs.SetupWithViewPager(viewPager);
//sends request for ad
var adView = FindViewById(Resource.Id.adView);
var adRequest = new AdRequest.Builder().AddTestDevice("04255CCF937684AD80A0FC1CE8235CFB").Build();
adView.LoadAd(adRequest);
adView.BringToFront();
用于主要布局的XML：
xmlns:android="/apk/res/android"
xmlns:app="/apk/res-auto"
xmlns:tools="/tools"
xmlns:ads="/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@+id/adView">
android:id="@+id/maintoolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
android:elevation="4dp"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent">
android:id="@+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
android:id="@+id/adView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
ads:adSize="SMART_BANNER"
ads:adUnitId="@string/banner_ad_unit_id"
android:layout_centerHorizontal="true"
android:layout_alignParentBottom="true">
adUnitId设置为'ca-app-pub-3940256099942544/6300978111'，这是提供的测试横幅。
当我在手机上启动我的应用程序(这是测试设备)时，广告不显示。
我在调试时遇到这些错误......
I/Ads ( 7518): Starting ad request.
09-02 13:59:53.617 I/Ads ( 7518): This request is sent from a test device.
09-02 13:59:53.619 W/Ads ( 7518): Not retrying to fetch app settings
09-02 13:59:54.028 I/Ads ( 7518): Instantiating mediation adapter: com.google.DummyAdapter
09-02 13:59:54.029 I/Ads ( 7518): No fill from any mediation ad networks.
09-02 13:59:54.075 I/Ads ( 7518): Scheduling ad refresh 60000 milliseconds from now.
09-02 13:59:54.075 W/Ads ( 7518): Failed to load ad: 3
