在unity singleton模式中使用admob奖励广告

using UnityEngine;
using GoogleMobileAds.Api;

public class AdManager : MonoBehaviour
{
    private static AdManager instance; // Singleton实例
    private RewardBasedVideoAd rewardAd; // 奖励广告实例

    public static AdManager Instance
    {
        get
        {
            if (instance == null)
            {
                instance = FindObjectOfType<AdManager>();
                DontDestroyOnLoad(instance.gameObject);
            }
            return instance;
        }
    }

    private void Awake()
    {
        if (instance == null)
        {
            instance = this;
            DontDestroyOnLoad(this.gameObject);
        }
        else
        {
            Destroy(gameObject);
        }
    }

    private void Start()
    {
        // 初始化奖励广告
        MobileAds.Initialize(initStatus => { });

        rewardAd = RewardBasedVideoAd.Instance;

        rewardAd.OnAdRewarded += HandleReward;
    }

    public void LoadRewardAd(string adUnitId)
    {
        AdRequest request = new AdRequest.Builder().Build();
        rewardAd.LoadAd(request, adUnitId);
    }

    public void ShowRewardAd()
    {
        if (rewardAd.IsLoaded())
        {
            rewardAd.Show();
        }
        else
        {
            Debug.Log("Reward ad is not ready yet.");
        }
    }

    private void HandleReward(object sender, Reward args)
    {
        // 处理奖励
    }
}