/// <summary>

/// 压缩和解压文件

/// </summary>

public class ZipClass

{

    /// <summary>

    /// 所有文件缓存

    /// </summary>

    List<string> files = new List<string>();  

    /// <summary>

    /// 所有空目录缓存

    /// </summary>

    List<string> paths = new List<string>();  

    /// <summary>

    /// 压缩单个文件

    /// </summary>

    /// <param name="fileToZip">要压缩的文件</param>

    /// <param name="zipedFile">压缩后的文件全名</param>

    /// <param name="compressionLevel">压缩程度，范围0-9，数值越大，压缩程序越高</param>

    /// <param name="blockSize">分块大小</param>

    public void ZipFile(string fileToZip, string zipedFile, int compressionLevel, int blockSize)

    {

        if (!System.IO.File.Exists(fileToZip))//如果文件没有找到，则报错

        {

            throw new FileNotFoundException("The specified file " + fileToZip + " could not be found. Zipping aborderd");

        }  

        FileStream streamToZip = new FileStream(fileToZip, FileMode.Open, FileAccess.Read);

        FileStream zipFile = File.Create(zipedFile);

        ZipOutputStream zipStream = new ZipOutputStream(zipFile);

        ZipEntry zipEntry = new ZipEntry(fileToZip);

        zipStream.PutNextEntry(zipEntry);

        zipStream.SetLevel(compressionLevel);

        byte[] buffer = new byte[blockSize];

        int size = streamToZip.Read(buffer, , buffer.Length);

        zipStream.Write(buffer, , size);  

        try

        {

            while (size < streamToZip.Length)

            {

                int sizeRead = streamToZip.Read(buffer, , buffer.Length);

                zipStream.Write(buffer, , sizeRead);

                size += sizeRead;

            }

        }

        catch (Exception ex)

        {

            GC.Collect();

            throw ex;

        }  

        zipStream.Finish();

        zipStream.Close();

        streamToZip.Close();

        GC.Collect();

    }  

    /// <summary>

    /// 压缩目录（包括子目录及所有文件）

    /// </summary>

    /// <param name="rootPath">要压缩的根目录</param>

    /// <param name="destinationPath">保存路径</param>

    /// <param name="compressLevel">压缩程度，范围0-9，数值越大，压缩程序越高</param>

    public void ZipFileFromDirectory(string rootPath, string destinationPath, int compressLevel)

    {

        GetAllDirectories(rootPath);  

        /* while (rootPath.LastIndexOf("\\") + 1 == rootPath.Length)//检查路径是否以"\"结尾

        { 

        rootPath = rootPath.Substring(0, rootPath.Length - 1);//如果是则去掉末尾的"\" 

        }

        */

        //string rootMark = rootPath.Substring(0, rootPath.LastIndexOf("\\") + 1);//得到当前路径的位置，以备压缩时将所压缩内容转变成相对路径。

        string rootMark = rootPath + "\\";//得到当前路径的位置，以备压缩时将所压缩内容转变成相对路径。

        Crc32 crc = new Crc32();

        ZipOutputStream outPutStream = new ZipOutputStream(File.Create(destinationPath));

        outPutStream.SetLevel(compressLevel); // 0 - store only to 9 - means best compression

        foreach (string file in files)

        {

            FileStream fileStream = File.OpenRead(file);//打开压缩文件

            byte[] buffer = new byte[fileStream.Length];

            fileStream.Read(buffer, , buffer.Length);

            ZipEntry entry = new ZipEntry(file.Replace(rootMark, string.Empty));

            entry.DateTime = DateTime.Now;

            // set Size and the crc, because the information

            // about the size and crc should be stored in the header

            // if it is not set it is automatically written in the footer.

            // (in this case size == crc == -1 in the header)

            // Some ZIP programs have problems with zip files that don't store

            // the size and crc in the header.

            entry.Size = fileStream.Length;

            fileStream.Close();

            crc.Reset();

            crc.Update(buffer);

            entry.Crc = crc.Value;

            outPutStream.PutNextEntry(entry);

            outPutStream.Write(buffer, , buffer.Length);

        }  

        this.files.Clear();  

        foreach (string emptyPath in paths)

        {

            ZipEntry entry = new ZipEntry(emptyPath.Replace(rootMark, string.Empty) + "/");

            outPutStream.PutNextEntry(entry);

        }  

        this.paths.Clear();

        outPutStream.Finish();

        outPutStream.Close();

        GC.Collect();

    }  

    /// <summary>

    /// 取得目录下所有文件及文件夹，分别存入files及paths

    /// </summary>

    /// <param name="rootPath">根目录</param>

    private void GetAllDirectories(string rootPath)

    {

        string[] subPaths = Directory.GetDirectories(rootPath);//得到所有子目录

        foreach (string path in subPaths)

        {

            GetAllDirectories(path);//对每一个字目录做与根目录相同的操作：即找到子目录并将当前目录的文件名存入List

        }

        string[] files = Directory.GetFiles(rootPath);

        foreach (string file in files)

        {

            this.files.Add(file);//将当前目录中的所有文件全名存入文件List

        }

        if (subPaths.Length == files.Length && files.Length == )//如果是空目录

        {

            this.paths.Add(rootPath);//记录空目录

        }

    }  

    /// <summary>

    /// 解压缩文件(压缩文件中含有子目录)

    /// </summary>

    /// <param name="zipfilepath">待解压缩的文件路径</param>

    /// <param name="unzippath">解压缩到指定目录</param>

    /// <returns>解压后的文件列表</returns>

    public List<string> UnZip(string zipfilepath, string unzippath)

    {

        //解压出来的文件列表

        List<string> unzipFiles = new List<string>();  

        //检查输出目录是否以“\\”结尾

        if (unzippath.EndsWith("\\") == false || unzippath.EndsWith(":\\") == false)

        {

            unzippath += "\\";

        }  

        ZipInputStream s = new ZipInputStream(File.OpenRead(zipfilepath));

        ZipEntry theEntry;

        while ((theEntry = s.GetNextEntry()) != null)

        {

            string directoryName = Path.GetDirectoryName(unzippath);

            string fileName = Path.GetFileName(theEntry.Name);  

            //生成解压目录【用户解压到硬盘根目录时，不需要创建】

            if (!string.IsNullOrEmpty(directoryName))

            {

                Directory.CreateDirectory(directoryName);

            }  

            if (fileName != String.Empty)

            {

                //如果文件的压缩后大小为0那么说明这个文件是空的,因此不需要进行读出写入

                if (theEntry.CompressedSize == )

                    break;

                //解压文件到指定的目录

                directoryName = Path.GetDirectoryName(unzippath + theEntry.Name);

                //建立下面的目录和子目录

                Directory.CreateDirectory(directoryName);  

                //记录导出的文件

                unzipFiles.Add(unzippath + theEntry.Name);  

                FileStream streamWriter = File.Create(unzippath + theEntry.Name);  

                int size = ;

                byte[] data = new byte[];

                while (true)

                {

                    size = s.Read(data, , data.Length);

                    if (size > )

                    {

                        streamWriter.Write(data, , size);

                    }

                    else

                    {

                        break;

                    }

                }

                streamWriter.Close();

            }

        }

        s.Close();

        GC.Collect();

        return unzipFiles;

    }

}