buildAsset分析（三）——BuildAssetBundle

当然前面两篇的都是为这篇的代码服务的。BuildAssetBundle.cs这个文件就是主要的打包assetbundle操作了。

首先是这些声明：

 //assetbundle资源    static string assetFilePath = "/assetbundles";    static string buildCfgFilePath = Application.dataPath + "/Editor/Build/build.txt";    static string levelCfgFilePath = Application.dataPath + "/Editor/Build/level.txt";    static string buildResourceCfg = Application.dataPath + "/Editor/Build/Resource.txt";    //打包环境设置    static BuildAssetBundleOptions options = BuildAssetBundleOptions.CollectDependencies | BuildAssetBundleOptions.CompleteAssets | BuildAssetBundleOptions.DeterministicAssetBundle;    static BuildTarget buildPlatform = BuildTarget.StandaloneWindows;    //保存所有的scene信息    static List<string> mScenes = new List<string>();    //保存所有Resource信息    static List<string> mResources = new List<string>();    //保存所有的Asset信息 场景+Resource    //保存所有要用到的资源，并按依赖数量分好了level    //int:代表level    //string：文件的路径，包括路径和文件名.    //AssetUnit:string文件的各种信息存放在这里面    static Dictionary<int, Dictionary<string, AssetUnit>> allLevelAssets = new Dictionary<int, Dictionary<string, AssetUnit>>();

然后接下来的3个函数不言而喻：
这三个函数都是放到editor中的，
显示到Editor中就是这样子的。

    //Andriod打包    [MenuItem("Build/BuildAndriod")]    public static void BuildAndriod()    {        buildPlatform = BuildTarget.Android;        BuildResourceFromUnityRule();    }    //IOS打包    [MenuItem("Build/BuildIOS")]    public static void BuildIOS()    {        buildPlatform = BuildTarget.iPhone;        BuildResourceFromUnityRule();    }    //Windows打包    [MenuItem("Build/BuildWindows")]    public static void BuildWindows()    {        buildPlatform = BuildTarget.StandaloneWindows;        BuildResourceFromUnityRule();    }

当然最主要的还是BuildResourceFromUnityRule()这个函数：

public static void BuildResourceFromUnityRule()    {        //清空数据        //assetbundleFilePath:Application.dataPath + "/assetbundles/"        if (Directory.Exists(ResourceCommon.assetbundleFilePath))            Directory.Delete(ResourceCommon.assetbundleFilePath, true);        //刷新数据        Caching.CleanCache();        AssetDatabase.Refresh();        //获取所有Scene信息        //通过自己定义的levelCfgFilePath目录的文件来获取所有Scene的路径，        //然后存到mScenes里面        GetBuildScenes();        //获取所有需要build的文件，        //然后保存到mResources中，当然保存的都是路径信息        GetBuildResources();        //get到所有mScenes和mResources中的        //资源的所有依赖，这样所有要用到的资源都get到了，        //然后按依赖个数把这些资源分等级。        //就是填充allLevelAssets这个Dictionary        GetAllAssets();        //保存Asset资源信息        //这个函数里面生成了所有文件(未打包)的XML信息，        //并保存到Assets/assetbundles/AssetInfo.bytes文件中        DumpAssetInfoFile();        //打包asset        //打包Assets/Resources下的所有资源（排除了无用资源）        //打包到Assets/assetbundles目录下        BuildResource();        //保存资源配置assetbundle        //所有打包好的资源的信息统一保存到        //Assets/assetbundles/Resource.bytes文件中(XML格式)        DumpResourceFile();        //根据所有assetbundle文件生成版本信息        //对每一个打包好的文件计算MD5值，        //并把文件基本信息存成XML文件version.bytes        //生成在Assets/assetbundles目录下，然后再复制到Assets/Resources目录下        //这里面也顺便把文件size存到了对应的AssetUnit里面        DumpVersionFile();        //根据生成的assetbundle文件大小填充 assetInfo.byte文件        //读取之前存到AssetUnit里面的的size，然后修改AssetInfo.bytes文件        AddAssetSizeToAssetInfoFile();        AssetDatabase.Refresh();        DebugEx.LogError("BuildResource finish", "BuildResource", true);    }

剩下的就是具体实现了，太长了，不过还是一下子贴出来好了：

//获取需要打包Resources目录下所有资源信息    //Assets/Resources目录下所有文件存到mResources里，除了meta文件和Version.bytes文件    [MenuItem("Build/Tools/GetBuildResources")]    public static void GetBuildResources()    {        mResources.Clear();        //Resource资源路径        string resourcePath = Application.dataPath + "/Resources/";        string[] files = Directory.GetFiles(resourcePath, "*.*", SearchOption.AllDirectories);        foreach (string file in files)        {            string suffix = BuildCommon.getFileSuffix(file);            if (suffix == "meta")                continue;            string realFile = file.Replace("\\", "/");            realFile = realFile.Replace(Application.dataPath, "Assets");            if (realFile == "Assets/Resources/Version.bytes")                continue;            mResources.Add(realFile);        }    }    //获取选中需要打包的Resources资源信息    [MenuItem("Build/Tools/GetSelectedBuildResources")]    public static void GetSelectedBuildResources()    {        mResources.Clear();        //Resource资源路径        //string resourcePath = Application.dataPath + "/Resources/";        //string[] files = Directory.GetFiles(resourcePath, "*.*", SearchOption.AllDirectories);        //foreach (string file in files)        //{        //    string suffix = BuildCommon.getFileSuffix(file);        //    if (suffix == "meta" || suffix == "cs")        //        continue;        //    string realFile = file.Replace("\\", "/");        //    realFile = realFile.Replace(Application.dataPath, "Assets");        //    mResources.Add(realFile);        //}        Object[] selection = Selection.GetFiltered(typeof(Object), SelectionMode.DeepAssets);        if (selection.Length == 0)            return;        foreach (Object obj in selection)        {            string assetPath = AssetDatabase.GetAssetPath(obj);            mResources.Add(assetPath);            Debug.Log("select:" + assetPath);        }    }    //获取需要打包的Scene目录下的所有资源信息    public static void GetBuildScenes()    {        mScenes.Clear();        //获取场景路径        FileStream fs = new FileStream(levelCfgFilePath, FileMode.Open);        StreamReader sr = new StreamReader(fs);        string path = "";        while (path != null)        {            if (path != "")            {                mScenes.Add(path);            }            path = sr.ReadLine();        }        sr.Close();        fs.Close();    }    [MenuItem("Build/Tools/TestSceneAssets")]    public static void TestSceneAssets()    {        string sceneName = "Assets/Scenes/1.unity";        string[] depends = AssetDatabase.GetDependencies(new string[] { sceneName });        foreach (string str in depends)        {            Debug.Log("depency: " + str);        }    }    //获取所有的Asset    [MenuItem("Build/Tools/GetAllAssets")]    public static void GetAllAssets()    {        //清空操作        allLevelAssets.Clear();        List<string> allAssetPath = new List<string>();        //1添加场景路径        foreach (string scene in mScenes)        {            allAssetPath.Add(scene);        }        //2添加Resource资源路径        foreach(string resrPath in mResources)        {            allAssetPath.Add(resrPath);        }        //获取场景以及预制件中所有的资源信息        //保存场景文件以及所有的resource文件的依赖        string[] allExportAssets = AssetDatabase.GetDependencies(allAssetPath.ToArray());        //这里allFiles好像声明了并没用过        Dictionary<string, AssetUnit> allFiles = new Dictionary<string, AssetUnit>();        foreach (string p in allExportAssets)        {            //if (p.Contains(".dll") || p.Contains(".cs"))            if (p.Contains(".dll"))                continue;            AssetUnit unit = new AssetUnit(p);            //Asset等级            //level最低是1.            int level = unit.mLevel;            //存在            if (allLevelAssets.ContainsKey(level))            {                allLevelAssets[level].Add(p, unit);            }            else             {                //添加等级                Dictionary<string, AssetUnit> levelAsset = new Dictionary<string, AssetUnit>();                allLevelAssets.Add(level,levelAsset);                //添加asset信息                allLevelAssets[level].Add(p, unit);            }        }        //创建Asset索引        BuildAssetUnitIndex();    }    [MenuItem("Build/Tools/CheckResources")]    public static void CheckResources()    {         AssetDatabase.Refresh();        //获取资源信息        GetBuildScenes();        GetBuildResources();        CheckAssetValid();        Debug.Log("Check finised");    }    [MenuItem("Build/Tools/BuildSelected")]    public static void BuildSelected()    {        //清空数据        if (Directory.Exists(ResourceCommon.assetbundleFilePath))            Directory.Delete(ResourceCommon.assetbundleFilePath, true);        //刷新数据        Caching.CleanCache();        AssetDatabase.Refresh();        //获取资源信息        GetBuildScenes();        GetSelectedBuildResources();        //获取所有的打包asset        GetAllAssets();        //保存Asset资源信息        DumpAssetInfoFile();        //打包asset        BuildResource();        //保存资源配置assetbundle        DumpResourceFile();        //根据所有assetbundle文件生成版本信息        DumpVersionFile();        //根据生成的assetbundle文件大小填充 assetInfo.byte文件         AddAssetSizeToAssetInfoFile();        AssetDatabase.Refresh();        DebugEx.LogError("BuildResource finish", "BuildResource", true);    }    public static void BuildResource()    {        AssetDatabase.Refresh();        //执行依赖性打包        //资源最大等级        int maxLevel = allLevelAssets.Count;        if (maxLevel == 0)            return;        //从最低等级开始打包        for (int level = 1; level <= maxLevel; level++)        {            //启用以下所有资源的交叉引用,            //直到调用PopAssetDependencies为止            //--这算是打包的必要步骤，            BuildPipeline.PushAssetDependencies();            //获取不同等级的aaset            Dictionary<string, AssetUnit> levelAssets = allLevelAssets[level];            //遍历该等级的所有asset打包            foreach(KeyValuePair<string, AssetUnit> pair in levelAssets)            {                //根据路径获取asset资源                Object asset = AssetDatabase.LoadMainAssetAtPath(pair.Value.mPath);                if (null == asset)                    DebugEx.LogError("load " + pair.Value.mPath + " failed!!!", "BuildResource", true);                //生成打包保存路径                //assetbundleFileSuffix = ".bytes";                string savePath = pair.Value.mPath.Insert(6, assetFilePath) + ResourceCommon.assetbundleFileSuffix;                BuildCommon.CheckFolder(BuildCommon.getPath(savePath));                //打包名称去Asset                //场景资源(xxx.unity)和普通资源分开                //普通资源                //打包成xxx.bytes文件                //可以到Assets/assetbundles这个目录下去看看                if (pair.Value.mSuffix != "unity")//普通资源                {                    string assetName = pair.Value.mPath.Replace("Assets/", "");                    //资源打包                    //这函数过时了                    if (!BuildPipeline.BuildAssetBundleExplicitAssetNames(                               new Object[] { asset }, new string[] { assetName }, savePath, options, buildPlatform))                        DebugEx.LogError("build assetbundle " + savePath + " failed!!!", "BuildResource", true);                }                //场景资源，没有依赖场景的                else                 {                    AssetDatabase.Refresh();                    BuildPipeline.PushAssetDependencies();                    string error = BuildPipeline.BuildStreamedSceneAssetBundle(new string[]{pair.Value.mPath}, savePath, buildPlatform);                    if (error != "")                        DebugEx.LogError(error, "BuildResource", true);                    BuildPipeline.PopAssetDependencies();                    Debug.Log("scene path" + pair.Value.mPath);                    //pair.Value.mPath                }            }           }        //popdepency依赖        for (int level = 1; level <= maxLevel; level++)        {            BuildPipeline.PopAssetDependencies();        }    }    //创建Asset资源信息    //把所有资源的信息保存到一个xml文件里面    public static void DumpAssetInfoFile()    {        if(allLevelAssets.Count ==0)            return;        ////创建所有资源Asset列表        XmlDocument doc = new XmlDocument();        XmlElement root = doc.CreateElement("AllAssets");        //遍历所有Asset数据        for (int level = 1; level <= allLevelAssets.Count; level++)        {            Dictionary<string, AssetUnit> levelAssets = allLevelAssets[level];            foreach (KeyValuePair<string, AssetUnit> asset in levelAssets)            {                string assetName = asset.Key;                AssetUnit assetUnit = asset.Value;                XmlElement ele = doc.CreateElement("Asset");                //设置路径名称                assetName = assetName.Replace("Assets/", "");                ele.SetAttribute("name", assetName);                //设置asset索引                ele.SetAttribute("index", assetUnit.mIndex.ToString());                //设置等级                ele.SetAttribute("level", level.ToString());                List<AssetUnit> sortDepencys = new List<AssetUnit>();                //获取AssetUnit所有依赖，并排序                List<string> depencys = assetUnit.mAllDependencies;                foreach (string depency in depencys)                {                    AssetUnit depencyUnit = GetAssetUnit(depency);                    sortDepencys.Add(depencyUnit);                }                //排序                sortDepencys.Sort(SortAssetUnit);                //保存依赖索引                string depencystr = "";                for (int i = 0; i < sortDepencys.Count; i++)                {                    AssetUnit unit = sortDepencys[i];                    if (i != sortDepencys.Count - 1)                        depencystr += unit.mIndex + ",";                    else                        depencystr += unit.mIndex;                }                ele.SetAttribute("depency", depencystr.ToString());                root.AppendChild(ele);            }        }        doc.AppendChild(root);        //这是assetbundleFilePath的声明:写在ResourceCommon里面        //public static string assetbundleFilePath = Application.dataPath + "/assetbundles/";        BuildCommon.CheckFolder(BuildCommon.getPath(ResourceCommon.assetbundleFilePath));        doc.Save(ResourceCommon.assetbundleFilePath + "AssetInfo.bytes");        Debug.Log("CreateAssetInfo success!!!");    }    //创建资源索引    public static void DumpResourceFile()    {        ////创建所有资源Asset列表        XmlDocument doc = new XmlDocument();        XmlElement root = doc.CreateElement("AllResources");        XmlElement resource = doc.CreateElement("Resources");        root.AppendChild(resource);        foreach (string res in mResources)        {            string ex = BuildCommon.getFileSuffix(res);            string path = res.Replace("Assets/", "");            //去掉后缀            path = path.Replace("." + ex, "");            XmlElement ele = doc.CreateElement("file");            ele.SetAttribute("name", path);            ele.SetAttribute("type", ex);            resource.AppendChild(ele);        }        //创建所有需要打包的Level列表        XmlElement sceneRes = doc.CreateElement("Level");        root.AppendChild(sceneRes);        foreach (string scene in mScenes)        {            XmlElement ele = doc.CreateElement("file");            string path = scene.Replace("Assets/", "");            path = path.Replace(".unity", "");            ele.SetAttribute("name", path);            ele.SetAttribute("type", "unity");            sceneRes.AppendChild(ele);        }        doc.AppendChild(root);        BuildCommon.CheckFolder(BuildCommon.getPath(ResourceCommon.assetbundleFilePath));        doc.Save(ResourceCommon.assetbundleFilePath + "Resource.bytes");        Debug.Log("CreateResourceCfg success!!!");    }    [MenuItem("Build/Tools/DumpVersionFile")]    public static void DumpVersionFile()    {        List<string> allFiles = new List<string>();        BuildCommon.GetFiles(ResourceCommon.assetbundleFilePath, allFiles, true);        XmlDocument doc = new XmlDocument();         XmlElement root = doc.CreateElement("Version");        root.SetAttribute("Number", "1.0.0");        root.SetAttribute("Big", "false");        foreach (string element in allFiles)        {            int size = 0;            string md5 = GetFileMD5(element, ref size);            XmlElement ele = doc.CreateElement("file");            string relativePath = element.Replace(Application.dataPath + "/assetbundles/", "");                      ele.SetAttribute("fpath", relativePath);            ele.SetAttribute("size", size.ToString());            ele.SetAttribute("md5", md5);            root.AppendChild(ele);            //保存大小信息到AssetUnit中            //一开始初始化AssetUnit的时候,size为0，            //在这里把size存进AssetUnit            string assetName = "Assets/" + relativePath;            assetName = assetName.Substring(0, assetName.Length - 6);            AssetUnit assetUnit = GetAssetUnit(assetName);            if(assetUnit != null)                assetUnit.mAssetSize = size;        }        doc.AppendChild(root);        string assetBundleVersionPath = ResourceCommon.assetbundleFilePath + "Version.bytes";        doc.Save(assetBundleVersionPath);        //拷贝到对应的Resource目录        string resourceVersionPath = Application.dataPath + "/Resources/" + "Version.bytes";        File.Copy(assetBundleVersionPath, resourceVersionPath, true);        Debug.Log("Dump Version Success!!!");    }    //添加asset信息    private static void AddAssetSizeToAssetInfoFile()    {        //添加asset信息        XmlDocument xmlDoc = new XmlDocument();        xmlDoc.Load(ResourceCommon.assetbundleFilePath + "AssetInfo.bytes");        XmlNodeList xnl = xmlDoc.SelectSingleNode("AllAssets").ChildNodes;         for (int i = 0; i < xnl.Count; i++)        {             XmlElement xe = (XmlElement)xnl.Item(i);            string assetName = xe.GetAttribute("name");            //获取对应的AssetUnit            AssetUnit unit = GetAssetUnit("Assets/" + assetName);            xe.SetAttribute("bundlesize", unit.mAssetSize.ToString());        }        xmlDoc.Save(ResourceCommon.assetbundleFilePath + "AssetInfo.bytes");    }    //计算文件MD5值，顺便获得文件size    //其实我觉得这函数写到BuildCommon里比较好    private static string GetFileMD5(string fpath, ref int size)    {        FileStream fs = new FileStream(fpath, FileMode.Open);        MD5 md5 = MD5.Create();        byte[] vals = md5.ComputeHash(fs);        string ret = BitConverter.ToString(vals);        ret = ret.Replace("-", "");        size = (int)fs.Length;        fs.Close();        return ret;    }    //按等级顺序创建AssetUnit的索引信息    //给allLevelAssets中的所有level中的所有AssetUnit的mIndex赋上值    //从level0的第一个AssetUnit开始，第一个AssetUnit的index为0，然后后面的AssetUnit依次index++    private static void BuildAssetUnitIndex()    {        if (allLevelAssets.Count == 0)            return;        int index = 0;        for (int level = 1; level <= allLevelAssets.Count; level++)        {            Dictionary<string, AssetUnit> levelAssets = allLevelAssets[level];            foreach (KeyValuePair<string, AssetUnit> pair in levelAssets)            {                AssetUnit unit = pair.Value;                unit.mIndex = index;                index++;            }        }         }    //根据Asset名称获取对应的AssetUnit    private static AssetUnit GetAssetUnit(string name)    {        if (allLevelAssets.Count == 0)            return null;        for (int level = 1; level <= allLevelAssets.Count; level++)        {            Dictionary<string, AssetUnit> assetUnit = allLevelAssets[level];            if (assetUnit.ContainsKey(name))                return assetUnit[name];        }        return null;    }     //检查所有的打包资源     private static void CheckAssetValid()     {          //清空操作        allLevelAssets.Clear();        List<string> allAssetPath = new List<string>();        //1添加场景路径        foreach (string scene in mScenes)        {            allAssetPath.Add(scene);        }        //2添加Resource资源路径        foreach(string resrPath in mResources)        {            allAssetPath.Add(resrPath);        }        //获取场景以及预制件中所有的资源信息        string[] allExportAssets = AssetDatabase.GetDependencies(allAssetPath.ToArray());        List<string> checkAssets = new List<string>();        foreach (string p in allExportAssets)        {            if (p.Contains(".dll"))                continue;            string assetName = Path.GetFileName(p);            assetName = assetName.ToLower();            if(checkAssets.Contains(assetName))            {                DebugEx.Log("the asset " + assetName + "has already exsited");            }            else            {                checkAssets.Add(assetName);            }        }     }    //对AssetUnit进行排序    private static int SortAssetUnit(AssetUnit unit1, AssetUnit unit2)    {        int res = 0;        if (unit1.mLevel > unit2.mLevel)        {            res = 1;        }        else if (unit1.mLevel < unit2.mLevel)        {            res = -1;        }        return res;    }}

太长了，不过文章开头应该能理清大概步骤了，然后后面很长的代码就是具体的实现代码，这样应该会好理解一些。