Unity AssetBundle打包工具示例详解

public class PathTools
{
    // 打包AB包根路径
    public const string AB_RESOURCES = "StreamingAssets"; 
    
    // 得到 AB 资源的输入目录
    public static string GetABResourcesPath()
    {
        return Application.dataPath + "/" + AB_RESOURCES;
    }

    // 获得 AB 包输出路径
    public static string GetABOutPath()
    {
        return GetPlatformPath() + "/" + GetPlatformName();
    }
    
    //获得平台路径
    private static string GetPlatformPath()
    {
        string strReturenPlatformPath = string.Empty;

#if UNITY_STANDALONE_WIN
        strReturenPlatformPath = Application.streamingAssetsPath;
#elif UNITY_IPHONE
            strReturenPlatformPath = Application.persistentDataPath;
#elif UNITY_ANDROID
            strReturenPlatformPath = Application.persistentDataPath;
#endif
        
        return strReturenPlatformPath;
    }
    
    // 获得平台名称
    public static string GetPlatformName()
    {
        string strReturenPlatformName = string.Empty;

#if UNITY_STANDALONE_WIN
        strReturenPlatformName = "Windows";
#elif UNITY_IPHONE
            strReturenPlatformName = "IPhone";
#elif UNITY_ANDROID
            strReturenPlatformName = "Android";
#endif

        return strReturenPlatformName;
    }
    
    // 返回 WWW 下载 AB 包加载路径
    public static string GetWWWAssetBundlePath()
    {
        string strReturnWWWPath = string.Empty;

#if UNITY_STANDALONE_WIN
        strReturnWWWPath = "file://" + GetABOutPath();
#elif UNITY_IPHONE
            strReturnWWWPath = GetABOutPath() + "/Raw/";
#elif UNITY_ANDROID
            strReturnWWWPath = "jar:file://" + GetABOutPath();
#endif

        return strReturnWWWPath;
    }
}

public class CreateAB : MonoBehaviour
{
    private static string abOutPath;
    private static List<AssetBundleBuild> listassets = new List<AssetBundleBuild>();
    private static List<DirectoryInfo> listfileinfo = new List<DirectoryInfo>();
    private static bool isover = false; //是否检查完成，可以打包
    static private string selectPath;

    public static bool GetState()
    {
        return isover;
    }

    public static AssetBundleBuild[] GetAssetBundleBuilds()
    {
        return listassets.ToArray();
    }

    [MenuItem("ABTools/CreatAB &_Q", false)]
    public static void CreateModelAB()
    {
        abOutPath = Application.streamingAssetsPath;

        if (!Directory.Exists(abOutPath))
            Directory.CreateDirectory(abOutPath);

        UnityEngine.Object obj = Selection.activeObject;
        selectPath = AssetDatabase.GetAssetPath(obj);
        SearchFileAssetBundleBuild(selectPath);
        
        BuildPipeline.BuildAssetBundles(abOutPath,
            CreateAB.GetAssetBundleBuilds(), BuildAssetBundleOptions.None, EditorUserBuildSettings.activeBuildTarget);
        Debug.Log("AssetBundle打包完毕");
    }

    [MenuItem("ABTools/CreatAB &_Q", true)]
    public static bool CanCreatAB()
    {
        if (Selection.objects.Length > 0)
        {
            return true;
        }
        else
            return false;
    }

//是文件，继续向下
    public static void SearchFileAssetBundleBuild(string path) 
    {
        DirectoryInfo directory = new DirectoryInfo(@path);
        FileSystemInfo[] fileSystemInfos = directory.GetFileSystemInfos();
        listfileinfo.Clear();
        //遍历所有文件夹中所有文件
        foreach (var item in fileSystemInfos)
        {
            int idx = item.ToString().LastIndexOf(@"\");
            string name = item.ToString().Substring(idx + 1);
            //item为文件夹，添加进listfileinfo，递归调用
            if ((item as DirectoryInfo) != null)
                listfileinfo.Add(item as DirectoryInfo);
            
            //剔除meta文件，其他文件都创建AssetBundleBuild,添加进listassets；
            if (!name.Contains(".meta"))
            {
                CheckFileOrDirectoryReturnBundleName(item, path + "/" + name);
            }
        }

        if (listfileinfo.Count == 0)
            isover = true;
        else
        {
            Debug.LogError(listfileinfo.Count);
        }
    }

    //判断是文件还是文件夹
    public static string CheckFileOrDirectoryReturnBundleName(FileSystemInfo fileSystemInfo, string path) 
    {
        FileInfo fileInfo = fileSystemInfo as FileInfo;
        if (fileInfo != null)
        {
            string[] strs = path.Split('.');
            string[] dictors = strs[0].Split('/');
            string name = "";
            for (int i = 1; i < dictors.Length; i++)
            {
                if (i < dictors.Length - 1)
                {
                    name += dictors[i] + "/";
                }
                else
                {
                    name += dictors[i];
                }
            }

            string[] strName = selectPath.Split('/');
            AssetBundleBuild assetBundleBuild = new AssetBundleBuild();
            assetBundleBuild.assetBundleName = strName[strName.Length - 1];
            assetBundleBuild.assetBundleVariant = "ab";
            assetBundleBuild.assetNames = new string[] {path};
            listassets.Add(assetBundleBuild);
            return name;
        }
        else
        {
            //递归调用
            SearchFileAssetBundleBuild(path);
            return null;
        }
    }
}

public class ClearABLable
{
    [MenuItem("ABTools/Remove AB Label")]
    public static void RemoveABLabel()
    {
        // 需要移除标记的根目录
        string strNeedRemoveLabelRoot = string.Empty;
        // 目录信息（场景目录信息数组，表示所有根目录下场景目录）
        DirectoryInfo[] directoryDIRArray = null;
        
        // 定义需要移除AB标签的资源的文件夹根目录
        strNeedRemoveLabelRoot = PathTools.GetABResourcesPath();   

        DirectoryInfo dirTempInfo = new DirectoryInfo(strNeedRemoveLabelRoot);
        directoryDIRArray = dirTempInfo.GetDirectories();

        // 遍历本场景目录下所有的目录或者文件
        foreach (DirectoryInfo currentDir in directoryDIRArray)
        {
            // 递归调用方法，找到文件，则使用 AssetImporter 类，标记“包名”与 “后缀名”
            JudgeDirOrFileByRecursive(currentDir);
        }

        // 清空无用的 AB 标记
        AssetDatabase.RemoveUnusedAssetBundleNames();
        // 刷新
        AssetDatabase.Refresh();

        // 提示信息，标记包名完成
        Debug.Log("AssetBundle 本次操作移除标记完成");
    }

    /// <summary>
    /// 递归判断判断是否是目录或文件
    /// 是文件，修改 Asset Bundle 标记
    /// 是目录，则继续递归
    /// </summary>
    /// <param name="fileSystemInfo">当前文件信息（文件信息与目录信息可以相互转换）</param>
    private static void JudgeDirOrFileByRecursive(FileSystemInfo fileSystemInfo)
    {
        // 参数检查
        if (fileSystemInfo.Exists == false)
        {
            Debug.LogError("文件或者目录名称：" + fileSystemInfo + " 不存在，请检查");
            return;
        }

        // 得到当前目录下一级的文件信息集合
        DirectoryInfo directoryInfoObj = fileSystemInfo as DirectoryInfo; 
        // 文件信息转为目录信息
        FileSystemInfo[] fileSystemInfoArray = directoryInfoObj.GetFileSystemInfos();

        foreach (FileSystemInfo fileInfo in fileSystemInfoArray)
        {
            FileInfo fileInfoObj = fileInfo as FileInfo;

            // 文件类型
            if (fileInfoObj != null)
            {
                // 修改此文件的 AssetBundle 标签
                RemoveFileABLabel(fileInfoObj);
            }
            // 目录类型
            else
            {
                // 如果是目录，则递归调用
                JudgeDirOrFileByRecursive(fileInfo);
            }
        }
    }

    /// <summary>
    /// 给文件移除 Asset Bundle 标记
    /// </summary>
    /// <param name="fileInfoObj">文件（文件信息）</param>
    static void RemoveFileABLabel(FileInfo fileInfoObj)
    {
        // AssetBundle 包名称
        string strABName = string.Empty;
        // 文件路径（相对路径）
        string strAssetFilePath = string.Empty;

        // 参数检查（*.meta 文件不做处理）
        if (fileInfoObj.Extension == ".meta")
        {
            return;
        }

        // 得到 AB 包名称
        strABName = string.Empty;
        // 获取资源文件的相对路径
        int tmpIndex = fileInfoObj.FullName.IndexOf("Assets");
        // 得到文件相对路径
        strAssetFilePath = fileInfoObj.FullName.Substring(tmpIndex); 
        
        // 给资源文件移除 AB 名称
        AssetImporter tmpImportObj = AssetImporter.GetAtPath(strAssetFilePath);
        tmpImportObj.assetBundleName = strABName;
    }
}