UNITY编辑器模式下static变量的坑

在unity中写编辑器扩展工具，如在编辑器中加个菜单，点击这个菜单项时执行打包功能。

类如下，其中的静态变量，如果每次进来不清空，则LIST会越来越大，打包函数执行完后系统不会帮我们清空

#if UNITY_EDITOR

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using UnityEditor;

using UnityEngine;
using LitJson;
using System.Security.Cryptography;

//资源清单，列出了游戏中用到的所有资源
[Serializable]
public class AssetsList
{
    /*** 资源清单
     * <相对路径, MD5串>
     */
    public Dictionary<string, string> Assets2Md5 = new Dictionary<string, string>();//容量未设置，后面可以写成常量，根据上次数据得出
}

public class AssetBundleBuilder
{
    public static string BundlePath = "";
    public static AssetsList AssetsList = new AssetsList();
    public static List<string> DependAssets_PathList = new List<string>(8000); //InGameRes所依赖的ArtSource等文件夹下的资源
    public static List<string> Assets_PathList = new List<string>(8000); //InGameRes文件夹下的资源
    public static List<AssetBundleBuild>  BuildList = new List<AssetBundleBuild>(18000); //估计值，后面可以写成常量，根据上次数据得出

    public static string ResRootPath = "Assets/Resources"; //资源目录，根据此目录查找所有依赖的资源
    public static string ResDependPath = "Assets/ArtSource"; //资源目录，根据此目录查找所有依赖的资源
    public static string ResFolder = "Resources"; //资源打包的依据文件夹，此文件夹下的所有文件及所有依赖文件都被打进AB包，不要在此文件夹下放备份或无用的资源

    public static string Depends_List_File = "Assets/depends_list.json";
    public static string Assets_List_File = "Assets/assets_list.json";

    public static int FileNumLimit = 10; //测试使用，只收集限定数量的文件
    public static void BuildAB(BuildTarget buildTarget)
    {
        if (!Directory.Exists(ResRootPath))
        {
            Debug.LogError("资源目录不存在：" + ResRootPath);
            return;
        }

        var files = Directory.GetFiles(ResRootPath, "*", SearchOption.AllDirectories);

        var stopwt = System.Diagnostics.Stopwatch.StartNew();
        var t1 = stopwt.ElapsedMilliseconds;

        /***
         * 坑，这里必须要清空，否则每次进来就会往Assets_PathList里添加一次内容
         */
        BuildList.Clear();
        Assets_PathList.Clear();
        DependAssets_PathList.Clear();
        AssetsList.Assets2Md5.Clear();

        var infoTitle = "收集文件，目录 : " + ResRootPath;
        //第一步，将ResRootPath目录下的文件收集起来，此目录的东西都是游戏中要用到的，此目录之外的东西不一定会用到
        var idx = 0;
        for (int i=0, cnt=files.Length; i<cnt; ++i)
        {
            var item = files[i];
            var ext = Path.GetExtension(item);
            if (string.Compare(ext, ".meta", true)==0 || string.Compare(ext, ".cs", true)==0)
                continue;

            if ((string.Compare(ext, ".prefab", true) == 0 || string.Compare(ext, ".mat", true) == 0
                || string.Compare(ext, ".unity", true) == 0 || string.Compare(ext, ".controller", true) == 0))
            {
                idx++;
                if (idx > FileNumLimit)
                    break;
                //添加到构建列表
                var abName = AddToBuildList(item);
                Assets_PathList.Add(abName);
            }

            EditorUtility.DisplayProgressBar(infoTitle, item, i * 1.0f / cnt);
        }

        WriteToJson(Assets_List_File, Assets_PathList);


        //第二步，将ResRootPath依赖的文件收集进来
        CheckAllDepends(files);

        var infoTitle2 = "收集依赖，目录 : " + ResDependPath;

        for (int i = 0, cnt = DependAssets_PathList.Count; i < cnt; ++i)
        {
            var item = DependAssets_PathList[i];

            //添加到构建列表
            AddToBuildList(item);

            EditorUtility.DisplayProgressBar(infoTitle2, item, i * 1.0f / cnt);
        }

        //第三步，增量打包
        var targetName = buildTarget == BuildTarget.iOS ? "IOS" : "Android";
        BundlePath = Application.dataPath.Substring(0, Application.dataPath.Length-6) + "Bundles" + targetName; //放到Assets同目录
        
        if (!Directory.Exists(BundlePath))
        {
            Directory.CreateDirectory(BundlePath);
        }

        var dt1 = stopwt.ElapsedMilliseconds - t1;

        ClearUnusedBundles(files);
        /***
         * 一次传入所有需要打包的数据，UNITY会保证它们之间的依赖被正确处理：先打被依赖的包，再打自己
         * 我们必须保证传入数据的完全，如果被依赖的包不在我们传入的列表中，则相应资源会被打到所有用到该包的包中，造成资源的重复包含
         */
        AssetBundleManifest manifest = BuildPipeline.BuildAssetBundles(BundlePath, BuildList.ToArray(), BuildAssetBundleOptions.ChunkBasedCompression, buildTarget);
        EditorUtility.ClearProgressBar();

        var dt2 = stopwt.ElapsedMilliseconds - t1 - dt1;

        EditorUtility.DisplayDialog("打包完成", "耗时：" + dt1 / 1000.0f + " + " + dt2/1000.0f + "
路径：" + BundlePath, "ok");

        GenResList(manifest);

        EditorUtility.UnloadUnusedAssetsImmediate();

    }

    public static string AddToBuildList(string resPath)
    {
        var relativeDir = resPath;

        //不能这样处理，因为可能有同名却不同后缀的文件存在
        //relativeDir = relativeDir.Substring(0, relativeDir.LastIndexOf(".")); //去除后缀
        relativeDir = relativeDir.Replace("\", "/");
        var abBuild = new AssetBundleBuild();
        abBuild.assetBundleName = relativeDir;
        abBuild.assetNames = new string[] { resPath };
        abBuild.assetBundleVariant = "ab";
        BuildList.Add(abBuild);

        return relativeDir;
    }

    //将AB包移动到StreamingAssets目录下，为打APK或IPA作准备
    public static void CopyToStreamingAssets(BuildTarget buildTarget)
    {
        CopyFolder(BundlePath, Application.streamingAssetsPath + "/Bundles/");
    }

    /***
     * 增量打包的关键，遍历上次打出的包，与本次【构建列表BuildList】里的内容对比，不在列表中的删除掉。
     * 在列表中的保留不变。这样当我们再次执行打包操作时，如果文件对应的AB包已存在且文件没有更改，则不用重新打包
     */
    public static void ClearUnusedBundles(string[] files)
    {
        if (!Directory.Exists(BundlePath))
        {
            Debug.LogError("包目录不存在：" + BundlePath);
            return;
        }

        var abFiles = Directory.GetFiles(BundlePath + "/assets", "*", SearchOption.AllDirectories);
        var delList = new List<string>();

        for (int i=0, n=abFiles.Length; i<n; ++i)
        {
            var ext = Path.GetExtension(abFiles[i]);
            var file = Path.ChangeExtension(abFiles[i], null);
            if(string.Compare(ext, ".manifest", true) == 0)
            {
                file = Path.ChangeExtension(file, null);
            }

            file = file.Substring(file.IndexOf("assets", StringComparison.CurrentCultureIgnoreCase));
            if (!File.Exists(file))
            {
                delList.Add(abFiles[i]);
            }

            EditorUtility.DisplayProgressBar("正在检查AssetBundle", file, i * 1.0f / n);

        }

        for (int i=0, n= delList.Count; i<n; ++i)
        {
            EditorUtility.DisplayProgressBar("正在清理无用的AssetBundle", delList[i], i * 1.0f / n);
            if (!File.Exists(delList[i]))
            {
                EditorUtility.DisplayDialog("", "不存在此文件", "ok");
                continue;
            }

            File.Delete(delList[i]);

        }

        EditorUtility.ClearProgressBar();

        WriteToJson("Assets/delete_list.json", delList);
    }

    //剪切到某个目录，并重命名
    public static void MoveFolder(string src, string dest)
    {
        if (Directory.Exists(dest))
        {
            Directory.Delete(dest, true);
        }
        Directory.CreateDirectory(dest);

        File.Move(src, dest + "/Bundles");
    }

    //复制到某个目录，并重命名
    public static void CopyFolder(string src, string dest)
    {
        if (Directory.Exists(dest))
        {
            Directory.Delete(dest, true);
        }
        Directory.CreateDirectory(dest);

        foreach (var sub in Directory.GetDirectories(src))
        {
            CopyFolder(sub + "/", dest + Path.GetFileName(sub) + "/");
        }

        foreach (var file in Directory.GetFiles(src))
        {
            File.Copy(file, dest + Path.GetFileName(file));
        }
    }

    /*** 生成资源清单
     * 格式：MD5 : 相对于/Bundles/的路径
     * 作用：热更的对比依据，通过MD5对比，确定文件的增-删-修改
     */
    public static void GenResList(AssetBundleManifest manifest)
    {
        AssetsList.Assets2Md5.Clear();

        var abs = manifest.GetAllAssetBundles();
        foreach (var ab in abs)
        {
            var hashes = manifest.GetAssetBundleHash(ab);
            AssetsList.Assets2Md5.Add(ab, hashes.ToString());
        }

        var writer = new JsonWriter();
        writer.PrettyPrint = true;
        JsonMapper.ToJson(AssetsList, writer);
        File.WriteAllText(BundlePath + "/asset_list.json", writer.ToString(), System.Text.Encoding.ASCII);

    }

    public static void DeleteBundles(BuildTarget target)
    {
        var path = Application.dataPath + "/../" + (target == BuildTarget.Android ? "BundlesAndroid" : "BundlesIOS");
        var msg = "文件夹不存在" + " " + path;
        if (Directory.Exists(path))
        {
            Directory.Delete(path, true);
            msg = "清理完成";
        }

        EditorUtility.DisplayDialog("清理", msg, "ok");
    }

    //得到指定文件夹下资源的所有依赖
    public static void CheckAllDepends(string targetPath)
    {
        if (!Directory.Exists(targetPath))
        {
            Debug.LogError("资源目录不存在：" + targetPath);
            return;
        }

        var files = Directory.GetFiles(targetPath, "*", SearchOption.AllDirectories);

        CheckAllDepends(files);
    }

    //得到指定文件的所有依赖
    public static void CheckAllDepends(string[] files)
    {
        var stopWatch = System.Diagnostics.Stopwatch.StartNew();
        var startTime = stopWatch.ElapsedMilliseconds;

        DependAssets_PathList.Clear();

        var idx = 0;
        for(int i=0, fileNum = files.Length; i< fileNum; ++i)
        {
            var item = files[i];
            var ext = Path.GetExtension(item);

            if (string.Compare(ext, ".meta", true) == 0 || string.Compare(ext, ".cs",true) == 0)
                continue;
            if ((string.Compare(ext, ".prefab", true) == 0 || string.Compare(ext, ".mat", true) == 0
                || string.Compare(ext, ".unity", true) == 0 || string.Compare(ext, ".controller", true) == 0))
            {
                idx++;
                if (idx > FileNumLimit)
                    break;

                var dpends = AssetDatabase.GetDependencies(item, true);
                foreach (var s in dpends)
                {
                    if (s.Contains(ResFolder) || s.Contains(".cs"))
                        continue;
                    //var substr = s.Substring(s.IndexOf("Assets/"));
                    if (!DependAssets_PathList.Contains(s))
                    {
                        DependAssets_PathList.Add(s);
                    }
                }
            }

            var progress = i *1.0f/ fileNum;
            EditorUtility.DisplayProgressBar("正在查找引用" + fileNum, item, progress);
        }

        EditorUtility.ClearProgressBar();

        //var savePath = "Assets/refs_list.json";
        WriteToJson(Depends_List_File, DependAssets_PathList);

        var deltaTime = stopWatch.ElapsedMilliseconds - startTime;

        EditorUtility.DisplayDialog("检查完成", "耗时" + deltaTime/1000.0f + "
保存路径: " + Depends_List_File, "ok");
    }

    public static void WriteToJson(string path, object obj)
    {
        var writer = new JsonWriter();
        writer.PrettyPrint = true;
        JsonMapper.ToJson(obj, writer);
        File.WriteAllText(path, writer.ToString());
    }

    [MenuItem("AssetBundle/安卓/构建AB包")]
    public static void BuildAndroidAB()
    {
        BuildAB(BuildTarget.Android);
    }

    [MenuItem("AssetBundle/IOS/构建AB包")]
    public static void BuildIOSAB()
    {
        BuildAB(BuildTarget.iOS);
    }

    [MenuItem("AssetBundle/安卓一键打包")]
    public static void AndroidOneKeyBuild()
    {
        BuildAB(BuildTarget.Android);
        CopyToStreamingAssets(BuildTarget.Android);
    }

    [MenuItem("AssetBundle/IOS一键打包")]
    public static void IOSOneKeyBuild()
    {
        BuildAB(BuildTarget.iOS);
        CopyToStreamingAssets(BuildTarget.iOS);
    }

    [MenuItem("AssetBundle/安卓/拷到StreamingAssets目录")]
    public static void CopyAndroidABToStreamingAssets()
    {
        CopyToStreamingAssets(BuildTarget.Android);
    }

    [MenuItem("AssetBundle/IOS/拷到StreamingAssets目录")]
    public static void CopyIOSABToStreamingAssets()
    {
        CopyToStreamingAssets(BuildTarget.iOS);
    }

    [MenuItem("AssetBundle/清理/清理安卓包")]
    public static void DeleteAndroidABs()
    {
        DeleteBundles(BuildTarget.Android);
    }

    [MenuItem("AssetBundle/清理/清理苹果包")]
    public static void DeleteIOSABs()
    {
        DeleteBundles(BuildTarget.iOS);
    }

    [MenuItem("AssetBundle/资源检查/检查依赖")]
    public static void CheckAssetsDepends()
    {
        CheckAllDepends(ResRootPath);
    }
}

#endif