/// <summary>
 /// 同步方式获取一个实体对象
 /// </summary>
 public GameObject Spawn(string resName)
 {
     if (_pools.ContainsKey(resName))
     {
         return(_pools[resName].Spawn());
     }
     else
     {
         // 如果不存在创建该实体的对象池
         AssetObjectPool pool = CreatePool(resName, 0);
         return(pool.Spawn());
     }
 }
 /// <summary>
 /// 异步方式获取一个实体对象
 /// </summary>
 public void Spawn(string resName, Action <GameObject> callbcak)
 {
     if (_pools.ContainsKey(resName))
     {
         _pools[resName].Spawn(callbcak);
     }
     else
     {
         // 如果不存在创建该实体的对象池
         AssetObjectPool pool = CreatePool(resName, 0);
         pool.Spawn(callbcak);
     }
 }