Java 如何在Xamarin.Android中实现RewardedLoadCallback？

我正在尝试在Xamarin.Android的C#中实现奖励广告

Android文档中的代码片段是用Java编写的，通常我在采用C#中的代码时不会遇到太多问题，但现在它似乎确实是个问题

要在Java中加载RewardedAd，必须执行以下（）操作：

现在这里的问题是，在这段代码中传递的对象

rewardedLoadCallback

也定义了方法实现（

onAdFailedToLoad

和

onAdLoaded

），而在C中，这是无法做到的

因此，我的解决方案是创建自己的类，

MyRewardedLoadCallback

，并重写这些方法

public class MyRewardedAdLoadCallback : RewardedAdLoadCallback
{
    public override void OnAdLoaded(Java.Lang.Object p0)
    {
        base.OnAdLoaded(p0);
    }

    public override void OnAdFailedToLoad(LoadAdError p0)
    {
        base.OnAdFailedToLoad(p0);
    }
}

然后，我只需加载带有以下代码的奖励广告：

AdRequest adRequest = new AdRequest.Builder().Build();

RewardedAd.Load(this, "ca-app-pub-3940256099942544/5224354917", adRequest, new MyRewardedAdLoadCallback());

现在由于某种奇怪的原因，我在构建项目时出现了以下错误：

error: name clash: onAdLoaded(Object) in MyRewardedAdLoadCallback and onAdLoaded(AdT) in AdLoadCallback have the same erasure, yet neither overrides the other
    public void onAdLoaded (java.lang.Object p0)
  where AdT is a type-variable:
    AdT extends Object declared in class AdLoadCallback

我试图在互联网上搜索这个错误，并得出结论，这是一个Java错误，与泛型类型有关（参见问题）。然而，我在我的代码中没有看到任何泛型类型，在Android文档中也没有关于奖励广告的内容。关于我试图实现的奖励广告，也没有Xamarin文档

---

如果有人能帮我解决这个问题，我真的很高兴。提前感谢。

这里有一个黑客程序，可以让Xamarin.GooglePlayServices.ads版本120.0.0中的间隙广告和奖励广告都能正常工作

将以下文件添加到您的项目中（需要使用不安全标志进行构建），并使用

Android.Gms.Ads.Hack

命名空间加载您的Ads并对回调进行子类化

例如，

interstitalad.Load

变成

global:：Android.Gms.Ads.Hack.interstitalad.Load

和

interstitalaldloadcallback

变成

global:：Android.Gms.Ads.Hack.interstitalaldloadcallback

回调类分别将

OnInterstitualAdLoaded（）

和

OnRewardedLoaded（）

虚拟方法添加到间隙和奖励ad加载回调中

using System;
using System.ComponentModel;
using System.Diagnostics;
using Android.Content;
using Android.Runtime;
using Java.Interop;

namespace Android.Gms.Ads.Hack
{
    public abstract class InterstitialAd : Java.Lang.Object
    {
        private static readonly JniPeerMembers _members = new XAPeerMembers("com/google/android/gms/ads/interstitial/InterstitialAd", typeof(InterstitialAd));

        public unsafe static void Load(Context context, string adUnit, AdRequest request, AdLoadCallback callback)
        {
            IntPtr intPtr = JNIEnv.NewString(adUnit);
            try
            {
                JniArgumentValue* ptr = stackalloc JniArgumentValue[4];
                *ptr = new JniArgumentValue(context?.Handle ?? IntPtr.Zero);
                ptr[1] = new JniArgumentValue(intPtr);
                ptr[2] = new JniArgumentValue(request?.Handle ?? IntPtr.Zero);
                ptr[3] = new JniArgumentValue(callback?.Handle ?? IntPtr.Zero);
                _members.StaticMethods.InvokeVoidMethod("load.(Landroid/content/Context;Ljava/lang/String;Lcom/google/android/gms/ads/AdRequest;Lcom/google/android/gms/ads/interstitial/InterstitialAdLoadCallback;)V", ptr);
            }
            finally
            {
                JNIEnv.DeleteLocalRef(intPtr);
                GC.KeepAlive(context);
                GC.KeepAlive(request);
                GC.KeepAlive(callback);
            }
        }
    }

    [Register("com/google/android/gms/ads/interstitial/InterstitialAdLoadCallback", DoNotGenerateAcw = true)]
    public abstract class InterstitialAdLoadCallback : AdLoadCallback
    {
        private static readonly JniPeerMembers _members = new XAPeerMembers("com/google/android/gms/ads/interstitial/InterstitialAdLoadCallback", typeof(InterstitialAdLoadCallback));

        static IntPtr class_ref => _members.JniPeerType.PeerReference.Handle;

        [DebuggerBrowsable(DebuggerBrowsableState.Never)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public override JniPeerMembers JniPeerMembers => _members;

        [DebuggerBrowsable(DebuggerBrowsableState.Never)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        protected override IntPtr ThresholdClass => _members.JniPeerType.PeerReference.Handle;

        [DebuggerBrowsable(DebuggerBrowsableState.Never)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        protected override Type ThresholdType => _members.ManagedPeerType;

        protected InterstitialAdLoadCallback(IntPtr javaReference, JniHandleOwnership transfer)
            : base(javaReference, transfer)
        {
        }

        [Register(".ctor", "()V", "")]
        public unsafe InterstitialAdLoadCallback()
            : base(IntPtr.Zero, JniHandleOwnership.DoNotTransfer)
        {
            if (!(base.Handle != IntPtr.Zero))
            {
                SetHandle(_members.InstanceMethods.StartCreateInstance("()V", GetType(), null).Handle, JniHandleOwnership.TransferLocalRef);
                _members.InstanceMethods.FinishCreateInstance("()V", this, null);
            }
        }

        private static Delegate cb_onAdLoaded;

        private static Delegate GetOnAdLoadedHandler()
        {
            if (cb_onAdLoaded is null)
            {
                cb_onAdLoaded = JNINativeWrapper.CreateDelegate((Action<IntPtr, IntPtr, IntPtr>)n_onAdLoaded);
            }

            return cb_onAdLoaded;
        }

        private static void n_onAdLoaded(IntPtr jnienv, IntPtr native__this, IntPtr native_p0)
        {
            InterstitialAdLoadCallback? @object = Java.Lang.Object.GetObject<InterstitialAdLoadCallback>(jnienv, native__this, JniHandleOwnership.DoNotTransfer);
            global::Android.Gms.Ads.Interstitial.InterstitialAd object2 = Java.Lang.Object.GetObject<global::Android.Gms.Ads.Interstitial.InterstitialAd>(native_p0, JniHandleOwnership.DoNotTransfer);
            @object!.OnInterstitialAdLoaded(object2);
        }

        [Register("onAdLoaded", "(Lcom/google/android/gms/ads/interstitial/InterstitialAd;)V", "GetOnAdLoadedHandler")]
        public virtual void OnInterstitialAdLoaded(global::Android.Gms.Ads.Interstitial.InterstitialAd interstitialAd)
        {
        }
    }

    public abstract class RewardedAd : Java.Lang.Object
    {
        private static readonly JniPeerMembers _members = new XAPeerMembers("com/google/android/gms/ads/rewarded/RewardedAd", typeof(RewardedAd));

        public unsafe static void Load(Context context, string adUnit, AdRequest request, RewardedAdLoadCallback callback)
        {
            IntPtr intPtr = JNIEnv.NewString(adUnit);
            try
            {
                JniArgumentValue* ptr = stackalloc JniArgumentValue[4];
                *ptr = new JniArgumentValue(context?.Handle ?? IntPtr.Zero);
                ptr[1] = new JniArgumentValue(intPtr);
                ptr[2] = new JniArgumentValue(request?.Handle ?? IntPtr.Zero);
                ptr[3] = new JniArgumentValue(callback?.Handle ?? IntPtr.Zero);
                _members.StaticMethods.InvokeVoidMethod("load.(Landroid/content/Context;Ljava/lang/String;Lcom/google/android/gms/ads/AdRequest;Lcom/google/android/gms/ads/rewarded/RewardedAdLoadCallback;)V", ptr);
            }
            finally
            {
                JNIEnv.DeleteLocalRef(intPtr);
                GC.KeepAlive(context);
                GC.KeepAlive(request);
                GC.KeepAlive(callback);
            }
        }
    }

    [Register("com/google/android/gms/ads/rewarded/RewardedAdLoadCallback", DoNotGenerateAcw = true)]
    public abstract class RewardedAdLoadCallback : AdLoadCallback
    {
        private static readonly JniPeerMembers _members = new XAPeerMembers("com/google/android/gms/ads/rewarded/RewardedAdLoadCallback", typeof(RewardedAdLoadCallback));

        static IntPtr class_ref => _members.JniPeerType.PeerReference.Handle;

        [DebuggerBrowsable(DebuggerBrowsableState.Never)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public override JniPeerMembers JniPeerMembers => _members;

        [DebuggerBrowsable(DebuggerBrowsableState.Never)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        protected override IntPtr ThresholdClass => _members.JniPeerType.PeerReference.Handle;

        [DebuggerBrowsable(DebuggerBrowsableState.Never)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        protected override Type ThresholdType => _members.ManagedPeerType;

        protected RewardedAdLoadCallback(IntPtr javaReference, JniHandleOwnership transfer)
            : base(javaReference, transfer)
        {
        }

        [Register(".ctor", "()V", "")]
        public unsafe RewardedAdLoadCallback()
            : base(IntPtr.Zero, JniHandleOwnership.DoNotTransfer)
        {
            if (!(base.Handle != IntPtr.Zero))
            {
                SetHandle(_members.InstanceMethods.StartCreateInstance("()V", GetType(), null).Handle, JniHandleOwnership.TransferLocalRef);
                _members.InstanceMethods.FinishCreateInstance("()V", this, null);
            }
        }

        private static Delegate cb_onAdLoaded;

        private static Delegate GetOnAdLoadedHandler()
        {
            if (cb_onAdLoaded is null)
            {
                cb_onAdLoaded = JNINativeWrapper.CreateDelegate((Action<IntPtr, IntPtr, IntPtr>)n_onAdLoaded);
            }

            return cb_onAdLoaded;
        }

        private static void n_onAdLoaded(IntPtr jnienv, IntPtr native__this, IntPtr native_p0)
        {
            RewardedAdLoadCallback? @object = Java.Lang.Object.GetObject<RewardedAdLoadCallback>(jnienv, native__this, JniHandleOwnership.DoNotTransfer);
            global::Android.Gms.Ads.Rewarded.RewardedAd object2 = Java.Lang.Object.GetObject<global::Android.Gms.Ads.Rewarded.RewardedAd>(native_p0, JniHandleOwnership.DoNotTransfer);
            @object!.OnRewardedAdLoaded(object2);
        }

        [Register("onAdLoaded", "(Lcom/google/android/gms/ads/rewarded/RewardedAd;)V", "GetOnAdLoadedHandler")]
        public virtual void OnRewardedAdLoaded(global::Android.Gms.Ads.Rewarded.RewardedAd rewardedAd)
        {
        }
    }
}

使用系统；
使用系统组件模型；
使用系统诊断；
使用Android.Content；
使用Android.Runtime；
使用Java.Interop；
名称空间Android.Gms.Ads.Hack
{
公共抽象类：Java.Lang.Object
{
私有静态只读jnipermembers\u成员=新的XAPeerMembers（“com/google/android/gms/ads/interstitual/interstitulard”，typeof（interstitulard））；
公共不安全静态无效加载（上下文上下文、字符串adUnit、AdRequest请求、AdLoadCallback）
{
IntPtr IntPtr=JNIEnv.NewString（adUnit）；
尝试
{
JniArgumentValue*ptr=stackalloc JniArgumentValue[4]；
*ptr=新的JniArgumentValue（context？.Handle？.IntPtr.Zero）；
ptr[1]=新的JniArgumentValue（intPtr）；
ptr[2]=新的JniArgumentValue（请求？.Handle？.IntPtr.Zero）；
ptr[3]=新的JniArgumentValue（回调？.Handle？.IntPtr.Zero）；
_members.StaticMethods.InvokeVoidMethod（“load.（Landroid/content/Context；Ljava/lang/String；Lcom/google/android/gms/ads/AdRequest；Lcom/google/android/gms/ads/interstitural/interstituralLoadCallback；）V”，ptr）；
}
最后
{
JNIEnv.DeleteLocalRef（intPtr）；
GC.KeepAlive（上下文）；
GC.KeepAlive（请求）；
GC.KeepAlive（回调）；
}
}
}
[注册（“com/google/android/gms/ads/interstitual/interstitularaldloadcallback”，DoNotGenerateAcw=true）]
公共抽象类AdLoadCallback:AdLoadCallback
{
private static readonly jnipermembers\u members=new XAPeerMembers（“com/google/android/gms/ads/interstitial/interstitialladloadcallback”，typeof（interstitialladloadcallback））；
静态IntPtr类_ref=>_members.jnipertype.PeerReference.Handle；
[DebuggerBrowsable（DebuggerBrowsableState.Never）]
[EditorBrowsable（EditorBrowsableState.Never）]
公共覆盖JNIperMembers JNIperMembers=>\u成员；
[DebuggerBrowsable（DebuggerBrowsableState.Never）]
[EditorBrowsable（EditorBrowsableState.Never）]
受保护的覆盖IntPtr ThresholdClass=>\u members.jniperType.PeerReference.Handle；
[DebuggerBrowsable（DebuggerBrowsableState.Never）]
[EditorBrowsable（EditorBrowsableState.Never）]
受保护的覆盖类型ThresholdType=>\u members.ManagedPeerType；
受保护的InterstitutionAladLoadCallback（IntPtr javaReference，JNIHandle所有权转移）
：base（javaReference，transfer）
{
}
[寄存器（“.ctor”，“（）V”，”）]
public-AladLoadCallback（）
：base（IntPtr.Zero、JniHandleOwnership.DoNotTransfer）
{
如果（！（base.Handle！=IntPtr.Zero））
{
SetHandle（_members.InstanceMethods.StartCreateInstance（“（）V”，GetType（），null）.Handle，JniHandleOwnership.TransferLocalRef）；
_members.InstanceMethods.FinishCreateInstance（（（）V），this，null）；
}
}
私有静态委托cb_已加载；
私有静态委托GetOnAdLoadedHandler（）
{
如果（cb_onAdLoaded为空）
{
cb_onAdLoaded=jniativewrapper.CreateDelegate（（操作）n_onAdLoaded）；
}
返回已加载的cb_；
}
已加载私有静态无效（IntPtr jnienv、IntPtr native、IntPtr native）
{
InterstitialLoadCallback？@object=Java.Lang.object.GetObject（jnienv，native\uu this，JniHandleOwnership.DoNotTransfer）；
全局：：Android.Gms.Ads.interstitual.interstitularad object2=Java.Lang.Object.GetObject（native_p0，JniHandleOwnership.DoNotTransfer）；
@对象！.onInterstitualAdLoaded（对象2）；
}
[注册（“onAdLoaded”），“（Lcom/google/android/gms/ads/Interstitual/InterstituralAD；
using System;
using System.ComponentModel;
using System.Diagnostics;
using Android.Content;
using Android.Runtime;
using Java.Interop;

namespace Android.Gms.Ads.Hack
{
    public abstract class InterstitialAd : Java.Lang.Object
    {
        private static readonly JniPeerMembers _members = new XAPeerMembers("com/google/android/gms/ads/interstitial/InterstitialAd", typeof(InterstitialAd));

        public unsafe static void Load(Context context, string adUnit, AdRequest request, AdLoadCallback callback)
        {
            IntPtr intPtr = JNIEnv.NewString(adUnit);
            try
            {
                JniArgumentValue* ptr = stackalloc JniArgumentValue[4];
                *ptr = new JniArgumentValue(context?.Handle ?? IntPtr.Zero);
                ptr[1] = new JniArgumentValue(intPtr);
                ptr[2] = new JniArgumentValue(request?.Handle ?? IntPtr.Zero);
                ptr[3] = new JniArgumentValue(callback?.Handle ?? IntPtr.Zero);
                _members.StaticMethods.InvokeVoidMethod("load.(Landroid/content/Context;Ljava/lang/String;Lcom/google/android/gms/ads/AdRequest;Lcom/google/android/gms/ads/interstitial/InterstitialAdLoadCallback;)V", ptr);
            }
            finally
            {
                JNIEnv.DeleteLocalRef(intPtr);
                GC.KeepAlive(context);
                GC.KeepAlive(request);
                GC.KeepAlive(callback);
            }
        }
    }

    [Register("com/google/android/gms/ads/interstitial/InterstitialAdLoadCallback", DoNotGenerateAcw = true)]
    public abstract class InterstitialAdLoadCallback : AdLoadCallback
    {
        private static readonly JniPeerMembers _members = new XAPeerMembers("com/google/android/gms/ads/interstitial/InterstitialAdLoadCallback", typeof(InterstitialAdLoadCallback));

        static IntPtr class_ref => _members.JniPeerType.PeerReference.Handle;

        [DebuggerBrowsable(DebuggerBrowsableState.Never)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public override JniPeerMembers JniPeerMembers => _members;

        [DebuggerBrowsable(DebuggerBrowsableState.Never)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        protected override IntPtr ThresholdClass => _members.JniPeerType.PeerReference.Handle;

        [DebuggerBrowsable(DebuggerBrowsableState.Never)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        protected override Type ThresholdType => _members.ManagedPeerType;

        protected InterstitialAdLoadCallback(IntPtr javaReference, JniHandleOwnership transfer)
            : base(javaReference, transfer)
        {
        }

        [Register(".ctor", "()V", "")]
        public unsafe InterstitialAdLoadCallback()
            : base(IntPtr.Zero, JniHandleOwnership.DoNotTransfer)
        {
            if (!(base.Handle != IntPtr.Zero))
            {
                SetHandle(_members.InstanceMethods.StartCreateInstance("()V", GetType(), null).Handle, JniHandleOwnership.TransferLocalRef);
                _members.InstanceMethods.FinishCreateInstance("()V", this, null);
            }
        }

        private static Delegate cb_onAdLoaded;

        private static Delegate GetOnAdLoadedHandler()
        {
            if (cb_onAdLoaded is null)
            {
                cb_onAdLoaded = JNINativeWrapper.CreateDelegate((Action<IntPtr, IntPtr, IntPtr>)n_onAdLoaded);
            }

            return cb_onAdLoaded;
        }

        private static void n_onAdLoaded(IntPtr jnienv, IntPtr native__this, IntPtr native_p0)
        {
            InterstitialAdLoadCallback? @object = Java.Lang.Object.GetObject<InterstitialAdLoadCallback>(jnienv, native__this, JniHandleOwnership.DoNotTransfer);
            global::Android.Gms.Ads.Interstitial.InterstitialAd object2 = Java.Lang.Object.GetObject<global::Android.Gms.Ads.Interstitial.InterstitialAd>(native_p0, JniHandleOwnership.DoNotTransfer);
            @object!.OnInterstitialAdLoaded(object2);
        }

        [Register("onAdLoaded", "(Lcom/google/android/gms/ads/interstitial/InterstitialAd;)V", "GetOnAdLoadedHandler")]
        public virtual void OnInterstitialAdLoaded(global::Android.Gms.Ads.Interstitial.InterstitialAd interstitialAd)
        {
        }
    }

    public abstract class RewardedAd : Java.Lang.Object
    {
        private static readonly JniPeerMembers _members = new XAPeerMembers("com/google/android/gms/ads/rewarded/RewardedAd", typeof(RewardedAd));

        public unsafe static void Load(Context context, string adUnit, AdRequest request, RewardedAdLoadCallback callback)
        {
            IntPtr intPtr = JNIEnv.NewString(adUnit);
            try
            {
                JniArgumentValue* ptr = stackalloc JniArgumentValue[4];
                *ptr = new JniArgumentValue(context?.Handle ?? IntPtr.Zero);
                ptr[1] = new JniArgumentValue(intPtr);
                ptr[2] = new JniArgumentValue(request?.Handle ?? IntPtr.Zero);
                ptr[3] = new JniArgumentValue(callback?.Handle ?? IntPtr.Zero);
                _members.StaticMethods.InvokeVoidMethod("load.(Landroid/content/Context;Ljava/lang/String;Lcom/google/android/gms/ads/AdRequest;Lcom/google/android/gms/ads/rewarded/RewardedAdLoadCallback;)V", ptr);
            }
            finally
            {
                JNIEnv.DeleteLocalRef(intPtr);
                GC.KeepAlive(context);
                GC.KeepAlive(request);
                GC.KeepAlive(callback);
            }
        }
    }

    [Register("com/google/android/gms/ads/rewarded/RewardedAdLoadCallback", DoNotGenerateAcw = true)]
    public abstract class RewardedAdLoadCallback : AdLoadCallback
    {
        private static readonly JniPeerMembers _members = new XAPeerMembers("com/google/android/gms/ads/rewarded/RewardedAdLoadCallback", typeof(RewardedAdLoadCallback));

        static IntPtr class_ref => _members.JniPeerType.PeerReference.Handle;

        [DebuggerBrowsable(DebuggerBrowsableState.Never)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public override JniPeerMembers JniPeerMembers => _members;

        [DebuggerBrowsable(DebuggerBrowsableState.Never)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        protected override IntPtr ThresholdClass => _members.JniPeerType.PeerReference.Handle;

        [DebuggerBrowsable(DebuggerBrowsableState.Never)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        protected override Type ThresholdType => _members.ManagedPeerType;

        protected RewardedAdLoadCallback(IntPtr javaReference, JniHandleOwnership transfer)
            : base(javaReference, transfer)
        {
        }

        [Register(".ctor", "()V", "")]
        public unsafe RewardedAdLoadCallback()
            : base(IntPtr.Zero, JniHandleOwnership.DoNotTransfer)
        {
            if (!(base.Handle != IntPtr.Zero))
            {
                SetHandle(_members.InstanceMethods.StartCreateInstance("()V", GetType(), null).Handle, JniHandleOwnership.TransferLocalRef);
                _members.InstanceMethods.FinishCreateInstance("()V", this, null);
            }
        }

        private static Delegate cb_onAdLoaded;

        private static Delegate GetOnAdLoadedHandler()
        {
            if (cb_onAdLoaded is null)
            {
                cb_onAdLoaded = JNINativeWrapper.CreateDelegate((Action<IntPtr, IntPtr, IntPtr>)n_onAdLoaded);
            }

            return cb_onAdLoaded;
        }

        private static void n_onAdLoaded(IntPtr jnienv, IntPtr native__this, IntPtr native_p0)
        {
            RewardedAdLoadCallback? @object = Java.Lang.Object.GetObject<RewardedAdLoadCallback>(jnienv, native__this, JniHandleOwnership.DoNotTransfer);
            global::Android.Gms.Ads.Rewarded.RewardedAd object2 = Java.Lang.Object.GetObject<global::Android.Gms.Ads.Rewarded.RewardedAd>(native_p0, JniHandleOwnership.DoNotTransfer);
            @object!.OnRewardedAdLoaded(object2);
        }

        [Register("onAdLoaded", "(Lcom/google/android/gms/ads/rewarded/RewardedAd;)V", "GetOnAdLoadedHandler")]
        public virtual void OnRewardedAdLoaded(global::Android.Gms.Ads.Rewarded.RewardedAd rewardedAd)
        {
        }
    }
}