为什么我写的代码没有问题，但应用程序没有出现广告？

Question

我正在尝试向我的 xamarin android 应用添加广告。我按照视频来做到这一点。但是当我完成时，我发现了一个 warning ( 'MobileAds.Initialize(Context, string)' is obsolete: 'deprecated' )，并且当我试图启动该程序时，广告不起作用。我尝试了大部分解决方案，但我的应用中没有出现任何广告。

这是主要的代码activity

using System;
using Android.App;
using Android.Content.PM;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using Android.Gms.Ads;

namespace App1.Droid
{
    [Activity(Label = "App1", Icon = "@mipmap/icon", Theme = "@style/MainTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation | ConfigChanges.UiMode | ConfigChanges.ScreenLayout | ConfigChanges.SmallestScreenSize )]
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
    protected override void OnCreate(Bundle savedInstanceState)
    {
        TabLayoutResource = Resource.Layout.Tabbar;
        ToolbarResource = Resource.Layout.Toolbar;
        base.OnCreate(savedInstanceState);
        MobileAds.Initialize(ApplicationContext, "ca-app-pub-3192508017252023~9595491677");
        Xamarin.Essentials.Platform.Init(this, savedInstanceState);
        global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
        LoadApplication(new App());
    }
    public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)
    {
        Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);

        base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
    }
}
}

这是AndroidManifest的代码

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
android:versionCode="1" android:versionName="1.0" package="com.companyname.app1">
<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="28" />
  <uses-permission android:name="android.permission.INTERNET" />
  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <application android:label="App1.Android" android:theme="@style/MainTheme">
  <meta-data
      android:name="com.google.android.gms.ads.APPLICATION_ID"
      android:value="ca-app-pub-3192508017252023~9595491677"/>
</application>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
</manifest>

这是 MainPage 的代码 XAML

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
         xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
         x:Class="App1.MainPage"
         xmlns:ads="clr-namespace:App1.Controls">
<StackLayout BackgroundColor="White">
    <RelativeLayout> 
    <Grid RowSpacing="0">
        <Grid.RowDefinitions>
            <RowDefinition Height="*"></RowDefinition>
            <RowDefinition Height="Auto"></RowDefinition>
        </Grid.RowDefinitions>
    </Grid>
        <StackLayout Grid.Row="0">
            <Label />
            <Button />
        </StackLayout>
    </RelativeLayout>
    <StackLayout HorizontalOptions="EndAndExpand">
        <ads:Ad_control_view BackgroundColor="Red"
                             HorizontalOptions="EndAndExpand"
                             Grid.Row="1"
                             >
            
        </ads:Ad_control_view>
    </StackLayout>
</StackLayout>

这是 class AdmobControl

using System;
using System.Collections.Generic;
using System.Text;
using Xamarin.Forms;

namespace App3.Controls
{
    public class AdmobControl :View
{
    public static readonly BindableProperty AdUnitIdProperty = BindableProperty.Create(
               nameof(AdUnitId),
               typeof(string),
               typeof(AdmobControl),
               string.Empty);

    public string AdUnitId
    {
        get => (string)GetValue(AdUnitIdProperty);
        set => SetValue(AdUnitIdProperty, value);
    }
}
}

这是Ad_control_view

using System;
using System.Collections.Generic;
using System.Text;
using Xamarin.Forms;

namespace App1.Controls
{
public class Ad_control_view:View
{
}

}

这是Ad_view_render

using Android.App;
using Android.Content;
using Android.Gms.Ads;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using App1.Controls;
using App1.Droid;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;

[assembly:ExportRenderer(typeof(Ad_control_view),typeof(Ad_view_render))]
namespace App1.Droid
{
public class Ad_view_render:ViewRenderer<Ad_control_view,AdView>
{
    public Ad_view_render(Context context):base(context)
    {

    }
    string ad_unit_id = "ca-app-pub-3192508017252023/5820253414";
    AdSize ad_size = AdSize.SmartBanner;
    AdView ad_view;
    private AdView Create_Ad_view()
    {
        if (ad_view != null)
            return ad_view;
        ad_view = new AdView(Context)
        {
            AdSize = ad_size,
            AdUnitId = ad_unit_id
        };
        var ad_params = new LinearLayout.LayoutParams(LayoutParams.WrapContent, LayoutParams.WrapContent);
        ad_view.LayoutParameters = ad_params;
        ad_view.LoadAd(new AdRequest.Builder().Build());
        return ad_view;
    }
    protected override void OnElementChanged(ElementChangedEventArgs<Ad_control_view> e)
    {
        base.OnElementChanged(e);
        if (Control==null&& e.NewElement!=null)
        {
            SetNativeControl(Create_Ad_view());
        }

    }
}
}

最后，这是警告信息

Severity Code Description Project File Line Suppression State Warning CS0618 'MobileAds.Initialize(Context, string)' is obsolete: 'deprecated' App1.Android C:\Users\Abo Ali\source\repos\App1\App1\App1.Android\MainActivity.cs 20 Active

Answer 1

使用最新版本的 AdMob，您将在不传递应用程序 ID 的情况下进行初始化（应用程序 ID 将从 AndroidManifest 中提取）：

base.OnCreate(bundle);
MobileAds.Initialize(this);

Answer 2

从 Visual Studio Nuget 包的 Xamarin.GooglePlayServices.Ads.Lite 版本 119.1.0 开始，我会更准确地回答这个问题。

MobileAds.Initialize(AndroidContext, "APP_ID") 已弃用。

所以您所要做的就是删除或注释那行代码，然后将这行代码添加到您的 AndroidManifest.xml

<manifest>
<application>
    <!-- Sample AdMob App ID: ca-app-pub-3940256099942544~3347511713 -->
    <meta-data
        android:name="com.google.android.gms.ads.APPLICATION_ID"
        android:value="ADMOB_APP_ID"/>
</application>
</manifest>

此包之前的所有版本都需要 MainActivity 的 OnCreate 方法中的代码行 Class。

希望这个回答对您有所帮助！

为什么我写的代码没有问题，但应用程序没有出现广告？

Why no ads appear in my application although I write the code correctly?

xamarin.android

xamarin.forms