如何在Xamarin.Android中实现RewardedAdLoadCallback？

RewardedAd rewardedAd = new RewardedAd(context, "your_ad_unit_id");

RewardedAdLoadCallback adLoadCallback = new RewardedAdLoadCallback
{
    OnAdLoaded = () =>
    {
        // 广告加载成功时的处理逻辑
    },
    OnAdFailedToLoad = (errorCode) =>
    {
        // 广告加载失败时的处理逻辑
    }
};

rewardedAd.LoadAd(new AdRequest.Builder().Build(), adLoadCallback);

using Android.Gms.Ads;
using Android.Gms.Ads.Reward;

public class MainActivity : AppCompatActivity
{
    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        SetContentView(Resource.Layout.activity_main);

        RewardedAd rewardedAd = new RewardedAd(this, "your_ad_unit_id");

        RewardedAdLoadCallback adLoadCallback = new RewardedAdLoadCallback
        {
            OnAdLoaded = () =>
            {
                // 广告加载成功时的处理逻辑
            },
            OnAdFailedToLoad = (errorCode) =>
            {
                // 广告加载失败时的处理逻辑
            }
        };

        rewardedAd.LoadAd(new AdRequest.Builder().Build(), adLoadCallback);
    }
}