/// <summary>
/// 释放ab包的接口，所以AB包释放都调用这个方法
/// </summary>
/// <param name="abName"></param>
public void DisposeAssetBundle(string abName)
{
AssetBundleItem bundleItem = null;
_AssetBundleDic.TryGetValue(abName, out bundleItem);
// 加载完的AB包才能卸载
if (bundleItem != null && bundleItem.BundleLoadStatus == BundleLoadStatus.LOADED)
{
//不在常驻内存列表的AB包才能卸载
if (abPermanentAsset == null || !abPermanentAsset.BundleNameHS.Contains(abName))
{
ABRelation abRelation = bundleItem.abRelation;
// 没有被别的包依赖才可以进行卸载
if (abRelation.GetAllReference().Count == 0)
{
bundleItem.Dispose(); // 卸载目标ab包
_AssetBundleDic.Remove(abName);
List <string> dependenceList = abRelation.GetAllDependence(); // 获取目标包所有依赖的包列表
foreach (string DependAbName in dependenceList)
{
bool isClear = _AssetBundleDic[DependAbName].abRelation.RemoveReference(abName); // 去掉目标包所依赖的包的被依赖关系
// 如果目标包所依赖的包已经没有被其他包依赖了，则把目标包所依赖的包也卸载掉（递归）
if (isClear)
{
DisposeAssetBundle(DependAbName);
}
}
}
}
}
}// function_end
