/// <summary>
        /// 加载依赖的AB包
        /// </summary>
        private IEnumerator LoadDependence(string abName, string refName)
        {
            ABRelation tempRelation;

            if (_abRelationDict.ContainsKey(abName))
            {
                //要依赖的包的对应关系类存在,直接给它添加引用关系
                tempRelation = _abRelationDict[abName];
                tempRelation.AddReference(refName);
            }
            else
            {
                //没有就创建关系类
                tempRelation = new ABRelation(abName);
                //为要依赖的包添加引用关系
                tempRelation.AddReference(refName);
                //放入字典
                _abRelationDict.Add(abName, tempRelation);
                //加载依赖的包(递归)
                yield return(LoadAssetBundle(abName));
            }
        }
        /// <summary>
        /// 加载AB包
        /// </summary>
        public IEnumerator LoadAssetBundle(string abName)
        {
            //判断AB包关系类是否已存在
            if (!_abRelationDict.ContainsKey(abName))
            {
                //创建和AB包名对应的AB包关系类加入字典
                ABRelation relation = new ABRelation(abName);
                _abRelationDict.Add(abName, relation);
            }

            //获取对应的关系类
            ABRelation tempRelation = _abRelationDict[abName];

            //得到指定AB包的所有依赖关系(查询清单文件)
            string[] dependenceArray = FrameworkEntry.ABManifestLoader.RetrivalDependece(abName);
            foreach (string itemDependence in dependenceArray)
            {
                //添加依赖项
                tempRelation.AddDependence(itemDependence);
                //加载它依赖的包
                yield return(LoadDependence(itemDependence, abName));
            }

            //是否已经加载过
            if (_singleABDict.ContainsKey(abName))
            {
                yield return(_singleABDict[abName].LoadAssetBundle());
            }
            else
            {
                //未加载过,创建对应的单包加载类对象
                _curSingleAB = new SingleABLoader_2(_curFirstDirName, abName, CompleteLoadAB);
                _singleABDict.Add(abName, _curSingleAB);
                yield return(_curSingleAB.LoadAssetBundle());
            }
        }