Unity android项目 AssetBundle 过多 导

可以使用合包的方式，将散的ab包合并到一个大的ab中

var destFileAB = Path.Combine(Setting.EditorStreamingBundlePath, "BigAssetBundle.ab");
var fileAB = new FileStream(destFileAB, FileMode.Create);
var head = new byte[] {0xAA, 0xBB, 0x10, 0x12};
fileAB.Write(head, 0, head.Length);

// 把需要打包进ab以及ab的依赖资源全部分进ab包内
for (var i = 0; i < bundleNames.Length; ++i){
    var hash = bundleNames[i].Substring(0, bundleNames[i].Length - 3 /*.ab*/);
    var finalName = hash + ".ab";
    if (abNames.Contains(finalName)){
            var nameDependencies = manifest.GetAllDependencies(bundleNames[i]);
            for (int j = 0; j < nameDependencies.Length; ++j){
                    if (!abNames.Contains(nameDependencies[j])){
                            abNames.Add(nameDependencies[j]);
                    }            
            }
    }
}

for (var i = 0; i < bundleNames.Length; ++i){
    var hash = bundleNames[i].Substring(0, bundleNames[i].Length - 3 /*.ab*/);
    var finalName = hash + ".ab";
    var sourceBytes = File.ReadAllBytes(Path.Combine(Setting.EditorBundleBuildCachePath, bundleNames[i]));
    if (abNames.Contains(finalName)){
            fileAB.Write(sourceBytes, 0, sourceBytes.Length);
    }
}

head 为加密，但是也没什么大用

如何分辨是合包AB还是散包AB

再构建散包的时候， offset=0 。构建合包资源的时候每个资源都记录有一个offset(资源大小字节偏移)
在加载的时候，如果 offset==0 的就是散包资源，否则是合包资源