在MAUI中通过Xamarin.GooglePlayServices.Ads.Lite集成AdMob遇问题求助

针对你遇到的三个问题，直接给出解决方案及完整实现示例：

问题1：Microsoft.Maui.Controls.Compatibility.Forms.Init() 重载找不到 #

直接移除该调用即可。MAUI 框架已经内置了 Forms 兼容层的初始化逻辑，不需要手动调用这个方法，Xamarin 时代的初始化步骤在 MAUI 中已被整合到启动流程里。

问题2：builder.SetTestDeviceIds 填入内容说明 #

这里必须填入测试设备ID，而非广告单元ID。测试设备ID用于标识你的测试设备，让 AdMob 返回测试广告，避免触发真实广告的计费规则及违反平台政策。
获取测试设备ID的方式：运行应用后，查看 Android Logcat 日志，找到类似以下内容的行，复制引号内的字符串即可：

Use AdRequest.Builder.addTestDevice("ABCDEFGHIJKLMNOPQRSTUVWXYZ") to get test ads on this device.

问题3：MAUI 中无 LoadApplication(new App()); 方法 #

MAUI 不需要手动调用这个方法。应用的加载逻辑已移至 MauiProgram.cs 的 CreateMauiApp 方法，框架会自动通过该方法返回的 MauiApp 实例完成应用启动，直接移除该调用即可。

完整原生广告实现示例 #

1. Android 项目初始化配置（Platforms/Android/MainApplication.cs） #

using Android.App;
using Android.Runtime;
using GoogleMobileAds;
using System.Collections.Generic;

namespace YourAppName.Droid;

[Application]
public class MainApplication : MauiApplication
{
    public MainApplication(IntPtr handle, JniHandleOwnership ownership)
        : base(handle, ownership)
    {
    }

    protected override MauiApp CreateMauiApp() => MauiProgram.CreateMauiApp();

    public override void OnCreate()
    {
        base.OnCreate();
        // 初始化 AdMob
        MobileAds.Initialize(ApplicationContext, _ => { });
        
        // 设置测试设备ID，替换为你的设备ID
        var config = new RequestConfiguration.Builder()
            .SetTestDeviceIds(new List<string> { "你的测试设备ID" })
            .Build();
        MobileAds.SetRequestConfiguration(config);
    }
}

2. 共享项目创建原生广告控件 #

using Microsoft.Maui.Controls;

namespace YourAppName;

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

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

3. Android 项目实现原生广告 Handler（替代Xamarin渲染器） #

先在 Android 项目的 Resources/layout 下创建 native_ad_layout.xml 布局文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="16dp"
    android:background="#f5f5f5">

    <TextView
        android:id="@+id/ad_attribution"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="12sp"
        android:textColor="#888"/>

    <ImageView
        android:id="@+id/ad_icon"
        android:layout_width="48dp"
        android:layout_height="48dp"
        android:layout_marginTop="8dp"/>

    <TextView
        android:id="@+id/ad_headline"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="16sp"
        android:textStyle="bold"
        android:layout_marginTop="8dp"/>

    <TextView
        android:id="@+id/ad_body"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="14sp"
        android:textColor="#444"
        android:layout_marginTop="4dp"/>

    <Button
        android:id="@+id/ad_call_to_action"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:background="#2196F3"
        android:textColor="#ffffff"/>
</LinearLayout>

然后创建 Handler 类：

using Android.Content;
using Android.Widget;
using GoogleMobileAds;
using GoogleMobileAds.Api;
using Microsoft.Maui.Handlers;
using YourAppName;
using YourAppName.Droid;

namespace YourAppName.Droid;

public class NativeAdViewHandler : ViewHandler<NativeAdView, FrameLayout>
{
    private NativeAdLoader _adLoader;
    private NativeAd _nativeAd;
    private FrameLayout _adContainer;

    protected override FrameLayout CreatePlatformView()
    {
        _adContainer = new FrameLayout(Context);
        LoadNativeAd();
        return _adContainer;
    }

    private void LoadNativeAd()
    {
        if (string.IsNullOrEmpty(VirtualView.AdUnitId)) return;

        var options = new NativeAdLoaderOptions.Builder().Build();
        _adLoader = new NativeAdLoader(Context, VirtualView.AdUnitId, new NativeAdListener(this));
        _adLoader.LoadAd(new AdRequest.Builder().Build());
    }

    private class NativeAdListener : AdListener
    {
        private readonly NativeAdViewHandler _handler;

        public NativeAdListener(NativeAdViewHandler handler) => _handler = handler;

        public override void OnAdLoaded(Ad ad)
        {
            base.OnAdLoaded(ad);
            if (ad is NativeAd nativeAd)
            {
                _handler._nativeAd = nativeAd;
                _handler.RenderNativeAd(nativeAd);
            }
        }
    }

    private void RenderNativeAd(NativeAd nativeAd)
    {
        var adView = LayoutInflater.From(Context).Inflate(Resource.Layout.native_ad_layout, _adContainer, false);

        // 绑定广告内容到布局控件
        (adView.FindViewById<TextView>(Resource.Id.ad_headline)).Text = nativeAd.Headline;
        (adView.FindViewById<TextView>(Resource.Id.ad_body)).Text = nativeAd.Body;
        (adView.FindViewById<Button>(Resource.Id.ad_call_to_action)).Text = nativeAd.CallToAction;
        if (nativeAd.Icon?.Drawable != null)
            (adView.FindViewById<ImageView>(Resource.Id.ad_icon)).SetImageDrawable(nativeAd.Icon.Drawable);
        (adView.FindViewById<TextView>(Resource.Id.ad_attribution)).Text = $"广告 · {nativeAd.Advertiser}";

        _adContainer.RemoveAllViews();
        _adContainer.AddView(adView);
    }

    protected override void DisconnectHandler()
    {
        _nativeAd?.Dispose();
        _adLoader?.Dispose();
        base.DisconnectHandler();
    }
}

4. 注册 Handler（MauiProgram.cs） #

using Microsoft.Maui.Hosting;
using YourAppName;
using YourAppName.Droid;

namespace YourAppName;

public static class MauiProgram
{
    public static MauiApp CreateMauiApp()
    {
        var builder = MauiApp.CreateBuilder();
        builder
            .UseMauiApp<App>()
            .ConfigureFonts(fonts =>
            {
                fonts.AddFont("OpenSans-Regular.ttf", "OpenSansRegular");
            });

        // 注册原生广告控件的Handler
        builder.ConfigureMauiHandlers(handlers =>
        {
#if ANDROID
            handlers.AddHandler(typeof(NativeAdView), typeof(NativeAdViewHandler));
#endif
        });

        return builder.Build();
    }
}

5. 在XAML中使用原生广告控件 #

<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:YourAppName"
             x:Class="YourAppName.MainPage">

    <StackLayout Padding="10">
        <!-- 其他页面内容 -->
        <Label Text="原生广告示例" FontSize="Large" Margin="0,20,0,10"/>
        <!-- 使用AdMob测试原生广告单元ID，上线替换为你的正式ID -->
        <local:NativeAdView AdUnitId="ca-app-pub-3940256099942544/2247696110" HeightRequest="300"/>
    </StackLayout>
</ContentPage>

内容的提问来源于stack exchange，提问作者Silny ToJa