Unity3d热更新（四）：压缩文件

之前提到过通过AssetBundle.CreateFromFile读取本地AssetBundle，因为该方法只能读取未压缩的AssetBundle，所以打包AssetBundle时，需要选择BuildAssetBundleOptions.UncompressedAssetBundle未压缩模式，然后使用LZMA或GZIP压缩后上传服务器。本地下载后需要解压缩保存在Application.persistentDataPath目录下。

下面说明如何压缩AssetBundle。

首先需要下载7-zip的C#核心文件，下载地址http://www.7-zip.org/sdk.html。

解压后将CS文件夹下的7zip文件夹导入Unity工程，下面是一个Demo，可以直接用。

using UnityEngine;using System.Collections;using UnityEditor;using SevenZip.Compression.LZMA;using System.IO;using System;// 压缩或解压文件public class CompressAndDecompress : Editor {    // 压缩Unity3D文件    [MenuItem("Compress/Compress Unity3D File")]    static void CompressUnity3DFile()    {        string path = EditorUtility.OpenFilePanel("Compress file", "", "unity3d");        CompressFile(path);    }    // 压缩Lua文件    [MenuItem("Compress/Compress Lua File")]    static void CompressLuaFile()    {        string path = EditorUtility.OpenFilePanel("Compress file", "", "lua");        CompressFile(path);    }    // 压缩文件    static void CompressFile(string path)    {        if (path.Length != 0)        {            int lastDotIndex = path.LastIndexOf(".");            string outputPath = path.Substring(0, lastDotIndex + 1) + "zip";            CompressFileLZMA(path, outputPath);            AssetDatabase.Refresh();            EditorUtility.DisplayDialog("压缩文件", "文件已压缩完成", "确认");        }    }    // 解压Unity3D文件    [MenuItem("Compress/Decompress Unity3D File")]    static void DecompressUnity3DFile()    {        DecompressFile("unity3d");    }    // 解压Lua文件    [MenuItem("Compress/Decompress Lua File")]    static void DecompressLuaFile()    {        DecompressFile("lua");    }    static void DecompressFile(string extension)    {        string path = EditorUtility.OpenFilePanel("Decompress file", "", "zip");        if (path.Length != 0)        {            int lastDotIndex = path.LastIndexOf(".");            string outputPath = path.Substring(0, lastDotIndex + 1) + extension;            DecompressFileLZMA(path, outputPath);            AssetDatabase.Refresh();            EditorUtility.DisplayDialog("解压文件", "文件已解压完成", "确认");        }    }    // 压缩文件夹中的文件    [MenuItem("Compress/Compress Files In Directory")]    static void CompressFilesInDirectory()    {        string path = EditorUtility.OpenFolderPanel("Compress Files In Directory", "", "");        if (path.Length != 0)        {            DirectoryInfo source = new DirectoryInfo(path);            DirectoryInfo target = new DirectoryInfo(path + "_compress");            if (target.Exists)            {                target.Delete(true);            }            target.Create();            target.Refresh();            // 复制源文件夹到目标文件夹            CopyAll(source, target);            ListFiles((FileSystemInfo)target, true);            EditorUtility.DisplayDialog("压缩文件夹", "文件夹中所有的文件已压缩完成", "确认");        }    }    // 解压文件夹中的文件    //[MenuItem("Compress/Decompress Files In Directory")]    static void DecompressFilesInDirectory()    {        string path = EditorUtility.OpenFolderPanel("Decompress Files In Directory", "", "");        if (path.Length != 0)        {            DirectoryInfo source = new DirectoryInfo(path);            DirectoryInfo target = new DirectoryInfo(path + "_decompress");            if (target.Exists)            {                target.Delete(true);            }            target.Create();            target.Refresh();            // 复制源文件夹到目标文件夹            CopyAll(source, target);            ListFiles(target, false);            EditorUtility.DisplayDialog("解压文件夹", "文件夹中所有的文件已解压完成", "确认");        }    }    // 使用LZMA算法压缩文件    private static void CompressFileLZMA(string inFile, string outFile)    {        Encoder coder = new Encoder();        FileStream input = new FileStream(inFile, FileMode.Open);        FileStream output = new FileStream(outFile, FileMode.Create);        coder.WriteCoderProperties(output);        byte[] data = BitConverter.GetBytes(input.Length);        output.Write(data, 0, data.Length);        coder.Code(input, output, input.Length, -1, null);        output.Flush();        output.Close();        input.Close();    }    // 使用LZMA算法解压文件    private static void DecompressFileLZMA(string inFile, string outFile)    {        Decoder coder = new Decoder();        FileStream input = new FileStream(inFile, FileMode.Open);        FileStream output = new FileStream(outFile, FileMode.Create);        byte[] properties = new byte[5];        input.Read(properties, 0, 5);        byte[] fileLengthBytes = new byte[8];        input.Read(fileLengthBytes, 0, 8);        long fileLength = BitConverter.ToInt64(fileLengthBytes, 0);        coder.SetDecoderProperties(properties);        coder.Code(input, output, input.Length, fileLength, null);        output.Flush();        output.Close();        input.Close();    }    // 复制源文件夹到目标文件夹    public static void CopyAll(DirectoryInfo source, DirectoryInfo target, ArrayList extensions = null)    {        if (source.FullName.ToLower() == target.FullName.ToLower())        {            return;        }        // 检测目标文件是否存在，如果不存在，则创建        if (!Directory.Exists(target.FullName))        {            Directory.CreateDirectory(target.FullName);            target.Refresh();        }        // 复制文件至目标文件夹        foreach (FileInfo fi in source.GetFiles())        {            if (extensions == null || extensions.Count == 0)            {                if (fi.Extension != ".meta")                {                    fi.CopyTo(Path.Combine(target.ToString(), fi.Name), true);                }            }            else            {                if (extensions.Contains(fi.Extension))                {                    fi.CopyTo(Path.Combine(target.ToString(), fi.Name), true);                }            }                    }        // 使用递归复制子文件夹        foreach (DirectoryInfo sourceSubDir in source.GetDirectories())        {            DirectoryInfo targetSubDir = target.CreateSubdirectory(sourceSubDir.Name);            CopyAll(sourceSubDir, targetSubDir, extensions);        }    }    // 遍历文件夹中的所有文件，压缩或解压缩    public static void ListFiles(FileSystemInfo info, bool isCompress)    {        if (!info.Exists)        {            return;        }        DirectoryInfo dir = info as DirectoryInfo;        // 不是目录        if (dir == null)        {            return;        }        FileSystemInfo[] files = dir.GetFileSystemInfos();        for (int i = 0; i < files.Length; i++)        {            FileInfo file = files[i] as FileInfo;            // 是文件            if (file != null)            {                string fullName = file.FullName;                // 如果是压缩文件                if (isCompress)                {                    if (file.Extension == ".unity3d" || file.Extension == ".lua")                    {                        string outputPath = file.FullName.Replace(file.Extension, ".zip");                        CompressFileLZMA(fullName, outputPath);                        File.Delete(fullName);                    }                }                // 如果是解压文件                else                {                    if (file.Extension == ".zip")                    {                        string outputPath = file.FullName.Replace(file.Extension, ".unity3d");                        DecompressFileLZMA(fullName, outputPath);                        File.Delete(fullName);                    }                }            }            else            {                ListFiles(files[i], isCompress);            }        }    }}