/// <summary>
        /// 加载AB包
        /// </summary>
        /// <param name="abName"></param>
        /// <returns></returns>
        public IEnumerator LoadAssetBundle(string abName)
        {
            //AB包关系的建立
            if (!_DicABRelation.ContainsKey(abName))
            {
                ABRelation abRelationObj = new ABRelation(abName);
                _DicABRelation.Add(abName, abRelationObj);
            }
            ABRelation tmpABReltation = _DicABRelation[abName];

            //得到指定AB包所有依赖关系(查询清单文件)
            string[] strDependenceArray = ABMainfestLoader.GetInstance().RetrivalDependce(abName);
            foreach (string item_Depence in strDependenceArray)
            {
                //添加 依赖项
                tmpABReltation.AddDependence(item_Depence);
                //添加引用项  递归调用
                yield return(LoadReference(item_Depence, abName));
            }

            //真正加载AB包
            if (_DicSingleABLoaderCache.ContainsKey(abName))
            {
                yield return(_DicSingleABLoaderCache[abName].LoadAssetBundle());
            }
            else
            {
                _CurrentSingleABLoader = new SingleABLoader(abName, CompleteLoadAB);
                _DicSingleABLoaderCache.Add(abName, _CurrentSingleABLoader);
                yield return(_CurrentSingleABLoader.LoadAssetBundle());
            }
        }
        /// <summary>
        /// 加载引用ab包
        /// </summary>
        /// <param name="abName">AB包名称</param>
        /// <param name="refABName">呗引用ab包名称</param>
        /// <returns></returns>
        private IEnumerator LoadReference(string abName, string refABName)
        {
            if (_DicABRelation.ContainsKey(abName))
            {
                ABRelation tmpABRelationObj = _DicABRelation[abName];
                //添加AB包引用关系(被依赖)
                tmpABRelationObj.AddReference(refABName);
            }
            else
            {
                ABRelation tmpABRelationObj = new ABRelation(abName);
                tmpABRelationObj.AddReference(refABName);
                _DicABRelation.Add(abName, tmpABRelationObj);

                //开始加载依赖的包
                yield return(LoadAssetBundle(abName));
            }
        }