C#- 压缩和解压缩的研究 .

用了第二种方法，感觉很不错，其他都没用过了。摘录下来，做一个备忘。

最近在网上查了一下在.net中进行压缩和解压缩的方法，方法有很多，我找到了以下几种：

1.利用.net自带的压缩和解压缩方法GZip

参考代码如下：

//========================================================================
    //  类名: CommonCompress
    /// <summary>
    /// 用于对文件和字符串进行压缩
    /// </summary>
    /// <remarks>
    /// 用于对文件和字符串进行压缩
    /// </remarks>
    /*=======================================================================
    变更记录
    序号　　　更新日期　　开发者　　　变更内容
    0001　　　2008/07/22  张          新建
    =======================================================================*/
    public class CommonCompress
    {
        /// <summary>
        /// 压缩字符串
        /// </summary>
        /// <param name="strUncompressed">未压缩的字符串</param>
        /// <returns>压缩的字符串</returns>
        public static string StringCompress(string strUncompressed)
        {
            byte[] bytData = System.Text.Encoding.Unicode.GetBytes(strUncompressed);
            MemoryStream ms = new MemoryStream();
            Stream s = new GZipStream(ms, CompressionMode.Compress);
            s.Write(bytData, , bytData.Length);
            s.Close();
            byte[] dataCompressed = (byte[])ms.ToArray();
            return System.Convert.ToBase64String(dataCompressed, , dataCompressed.Length);
        }

        /// <summary>
        /// 解压缩字符串
        /// </summary>
        /// <param name="strCompressed">压缩的字符串</param>
        /// <returns>未压缩的字符串</returns>
        public static string StringDeCompress(string strCompressed)
        {
            System.Text.StringBuilder strUncompressed = new System.Text.StringBuilder();
            int totalLength = ;
            byte[] bInput = System.Convert.FromBase64String(strCompressed); ;
            byte[] dataWrite = new byte[];
            Stream s = new GZipStream(new MemoryStream(bInput), CompressionMode.Decompress);
            while (true)
            {
                int size = s.Read(dataWrite, , dataWrite.Length);
                if (size > )
                {
                    totalLength += size;
                    strUncompressed.Append(System.Text.Encoding.Unicode.GetString(dataWrite, , size));
                }
                else
                {
                    break;
                }
            }
            s.Close();
            return strUncompressed.ToString();
        }

        /// <summary>
        /// 压缩文件
        /// </summary>
        /// <param name="iFile">压缩前文件路径</param>
        /// <param name="oFile">压缩后文件路径</param>
        public static void CompressFile(string iFile, string oFile)
        {
            //判断文件是否存在
            if (File.Exists(iFile) == false)
            {
                throw new FileNotFoundException("文件未找到!");
            }
            //创建文件流
            byte[] buffer = null;
            FileStream iStream = null;
            FileStream oStream = null;
            GZipStream cStream = null;
            try
            {
                //把文件写进数组
                iStream = new FileStream(iFile, FileMode.Open, FileAccess.Read, FileShare.Read);
                buffer = new byte[iStream.Length];
                int num = iStream.Read(buffer, , buffer.Length);
                if (num != buffer.Length)
                {
                    throw new ApplicationException("压缩文件异常!");
                }
                //创建文件输出流并输出
                oStream = new FileStream(oFile, FileMode.OpenOrCreate, FileAccess.Write);
                cStream = new GZipStream(oStream, CompressionMode.Compress, true);
                cStream.Write(buffer, , buffer.Length);
            }
            finally
            {
                //关闭流对象
                if (iStream != null) iStream.Close();
                if (cStream != null) cStream.Close();
                if (oStream != null) oStream.Close();
            }
        }

        /// <summary>
        /// 解压缩文件
        /// </summary>
        /// <param name="iFile">压缩前文件路径</param>
        /// <param name="oFile">压缩后文件路径</param>
        public static void DecompressFile(string iFile, string oFile)
        {
            //判断文件是否存在
            if (File.Exists(iFile) == false)
            {
                throw new FileNotFoundException("文件未找到!");
            }
            //创建文件流
            FileStream iStream = null;
            FileStream oStream = null;
            GZipStream dStream = null;
            byte[] qBuffer = new byte[];
            try
            {
                //把压缩文件写入数组
                iStream = new FileStream(iFile, FileMode.Open);
                dStream = new GZipStream(iStream, CompressionMode.Decompress, true);
                int position = (int)iStream.Length - ;
                iStream.Position = position;
                iStream.Read(qBuffer, , );
                iStream.Position = ;
                int num = BitConverter.ToInt32(qBuffer, );
                byte[] buffer = new byte[num + ];
                int offset = , total = ;
                while (true)
                {
                    int bytesRead = dStream.Read(buffer, offset, );
                    if (bytesRead == ) break;
                    offset += bytesRead;
                    total += bytesRead;
                }
                //创建输出流并输出
                oStream = new FileStream(oFile, FileMode.Create);
                oStream.Write(buffer, , total);
                oStream.Flush();
            }
            finally
            {
                //关闭流对象
                if (iStream != null) iStream.Close();
                if (dStream != null) dStream.Close();
                if (oStream != null) oStream.Close();
            }
        }
    }

2.利用ICSharpCode的压缩和解压缩方法,需引用ICSharpCode.SharpZipLib.dll,这个类库是开源的，源码地址http://www.icsharpcode.net/OpenSource/SharpZipLib/Download.aspx

参考代码如下：

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

using ICSharpCode.SharpZipLib.Zip;
using ICSharpCode.SharpZipLib.Checksums;

namespace ZYBNET.FW.Utility.CommonMethod
{
    //========================================================================
    //  类名: ZipHelper
    /// <summary>
    /// 用于对文件和字符串进行压缩
    /// </summary>
    /// <remarks>
    /// 用于对文件和字符串进行压缩
    /// </remarks>
    /*=======================================================================
    变更记录
    序号　　　更新日期　　开发者　　　变更内容
    0001　　　2008/07/22  张          新建
    =======================================================================*/
    public class ZipHelper
    {
        #region 压缩文件夹,支持递归
        /// <summary>
        ///　压缩文件夹
        /// </summary>
        /// <param name="dir">待压缩的文件夹</param>
        /// <param name="targetFileName">压缩后文件路径（包括文件名）</param>
        /// <param name="recursive">是否递归压缩</param>
        /// <returns></returns>
        public static bool Compress(string dir, string targetFileName, bool recursive)
        {
            //如果已经存在目标文件，询问用户是否覆盖
            if (File.Exists(targetFileName))
            {
                throw new Exception("同名文件已经存在！");
            }
            string[] ars = new string[];
            if (recursive == false)
            {
                ars[] = dir;
                ars[] = targetFileName;
                return ZipFileDictory(ars);
            }

            FileStream zipFile;
            ZipOutputStream zipStream;

            //打开压缩文件流
            zipFile = File.Create(targetFileName);
            zipStream = new ZipOutputStream(zipFile);

            if (dir != String.Empty)
            {
                CompressFolder(dir, zipStream, dir);
            }

            //关闭压缩文件流
            zipStream.Finish();
            zipStream.Close();

            if (File.Exists(targetFileName))
                return true;
            else
                return false;
        }

        /// <summary>
        /// 压缩目录
        /// </summary>
        /// <param name="args">数组(数组[0]: 要压缩的目录; 数组[1]: 压缩的文件名)</param>
        public static bool ZipFileDictory(string[] args)
        {
            ZipOutputStream zStream = null;
            try
            {
                string[] filenames = Directory.GetFiles(args[]);
                Crc32 crc = new Crc32();
                zStream = new ZipOutputStream(File.Create(args[]));
                zStream.SetLevel();
                //循环压缩文件夹中的文件
                foreach (string file in filenames)
                {
                    //打开压缩文件
                    FileStream fs = File.OpenRead(file);
                    byte[] buffer = new byte[fs.Length];
                    fs.Read(buffer, , buffer.Length);
                    ZipEntry entry = new ZipEntry(file);
                    entry.DateTime = DateTime.Now;
                    entry.Size = fs.Length;
                    fs.Close();
                    crc.Reset();
                    crc.Update(buffer);
                    entry.Crc = crc.Value;
                    zStream.PutNextEntry(entry);
                    zStream.Write(buffer, , buffer.Length);
                }
            }
            catch
            {
                throw;
            }
            finally
            {
                zStream.Finish();
                zStream.Close();
            }
            return true;
        }

        /// <summary>
        /// 压缩某个子文件夹
        /// </summary>
        /// <param name="basePath">待压缩路径</param>
        /// <param name="zips">压缩文件流</param>
        /// <param name="zipfolername">待压缩根路径</param>
        private static void CompressFolder(string basePath, ZipOutputStream zips, string zipfolername)
        {
            if (File.Exists(basePath))
            {
                AddFile(basePath, zips, zipfolername);
                return;
            }
            string[] names = Directory.GetFiles(basePath);
            foreach (string fileName in names)
            {
                AddFile(fileName, zips, zipfolername);
            }

            names = Directory.GetDirectories(basePath);
            foreach (string folderName in names)
            {
                CompressFolder(folderName, zips, zipfolername);
            }

        }

        /// <summary>
        ///　压缩某个子文件
        /// </summary>
        /// <param name="fileName">待压缩文件</param>
        /// <param name="zips">压缩流</param>
        /// <param name="zipfolername">待压缩根路径</param>
        private static void AddFile(string fileName, ZipOutputStream zips, string zipfolername)
        {
            if (File.Exists(fileName))
            {
                CreateZipFile(fileName, zips, zipfolername);
            }
        }

        /// <summary>
        /// 压缩单独文件
        /// </summary>
        /// <param name="FileToZip">待压缩文件</param>
        /// <param name="zips">压缩流</param>
        /// <param name="zipfolername">待压缩根路径</param>
        private static void CreateZipFile(string FileToZip, ZipOutputStream zips, string zipfolername)
        {
            try
            {
                FileStream StreamToZip = new FileStream(FileToZip, FileMode.Open, FileAccess.Read);
                string temp = FileToZip;
                string temp1 = zipfolername;
                if (temp1.Length > )
                {
                    temp = temp.Replace(zipfolername + "\\", "");
                }
                ZipEntry ZipEn = new ZipEntry(temp);

                zips.PutNextEntry(ZipEn);
                byte[] buffer = new byte[];
                System.Int32 size = StreamToZip.Read(buffer, , buffer.Length);
                zips.Write(buffer, , size);
                try
                {
                    while (size < StreamToZip.Length)
                    {
                        int sizeRead = StreamToZip.Read(buffer, , buffer.Length);
                        zips.Write(buffer, , sizeRead);
                        size += sizeRead;
                    }
                }
                catch (System.Exception ex)
                {
                    throw ex;
                }

                StreamToZip.Close();
            }
            catch
            {
                throw;
            }
        }
        #endregion

        #region 解压缩
        /// <summary>
        /// 功能：解压zip格式的文件。
        /// </summary>
        /// <param name="zipFilePath">压缩文件路径</param>
        /// <param name="unZipDir">解压文件存放路径,为空时默认与压缩文件同一级目录下，跟压缩文件同名的文件夹</param>
        /// <returns>解压是否成功</returns>
        public static void UnZipFile(string zipFilePath, string unZipDir)
        {

            if (zipFilePath == string.Empty)
            {
                throw new Exception("压缩文件不能为空！");
            }
            if (!File.Exists(zipFilePath))
            {
                throw new Exception("压缩文件不存在！");
            }
            //解压文件夹为空时默认与压缩文件同一级目录下，跟压缩文件同名的文件夹
            if (unZipDir == string.Empty)
                unZipDir = zipFilePath.Replace(Path.GetFileName(zipFilePath), Path.GetFileNameWithoutExtension(zipFilePath));
            if (!unZipDir.EndsWith("//"))
                unZipDir += "//";
            if (!Directory.Exists(unZipDir))
                Directory.CreateDirectory(unZipDir);

            try
            {
                using (ZipInputStream s = new ZipInputStream(File.OpenRead(zipFilePath)))
                {
                    ZipEntry theEntry;
                    while ((theEntry = s.GetNextEntry()) != null)
                    {
                        string directoryName = Path.GetDirectoryName(theEntry.Name);
                        string fileName = Path.GetFileName(theEntry.Name);
                        if (directoryName.Length > )
                        {
                            Directory.CreateDirectory(unZipDir + directoryName);
                        }
                        if (!directoryName.EndsWith("//"))
                            directoryName += "//";
                        if (fileName != String.Empty)
                        {
                            using (FileStream streamWriter = File.Create(unZipDir + theEntry.Name))
                            {
                                int size = ;
                                byte[] data = new byte[];
                                while (true)
                                {
                                    size = s.Read(data, , data.Length);
                                    if (size > )
                                    {
                                        streamWriter.Write(data, , size);
                                    }
                                    else
                                    {
                                        break;
                                    }
                                }
                            }
                        }
                    }
                }
            }
            catch
            {
                throw;
            }
        }
        #endregion

    }
}

3.利用java的压缩和解压缩方法,需引用vjslib.dll

至于这种方法的使用，大家可以去查阅msdn,这里就不写了

4.利用zlibwapi.dll的API进行压缩

据说压缩效率比较好，但是在网上没找到供下载的链接，有兴趣的朋友可以试试

5.使用System.IO.Packaging压缩和解压

System.IO.Packaging在WindowsBase.dll程序集下，使用时需要添加对WindowsBase的引用

/// <summary>
        /// Add a folder along with its subfolders to a Package
        /// </summary>
        /// <param name="folderName">The folder to add</param>
        /// <param name="compressedFileName">The package to create</param>
        /// <param name="overrideExisting">Override exsisitng files</param>
        /// <returns></returns>
        static bool PackageFolder(string folderName, string compressedFileName, bool overrideExisting)
        {
            if (folderName.EndsWith(@"\"))
                folderName = folderName.Remove(folderName.Length - );
            bool result = false;
            if (!Directory.Exists(folderName))
            {
                return result;
            }

            if (!overrideExisting && File.Exists(compressedFileName))
            {
                return result;
            }
            try
            {
                using (Package package = Package.Open(compressedFileName, FileMode.Create))
                {
                    var fileList = Directory.EnumerateFiles(folderName, "*", SearchOption.AllDirectories);
                    foreach (string fileName in fileList)
                    {

                        //The path in the package is all of the subfolders after folderName
                        string pathInPackage;
                        pathInPackage = Path.GetDirectoryName(fileName).Replace(folderName, string.Empty) + "/" + Path.GetFileName(fileName);

                        Uri partUriDocument = PackUriHelper.CreatePartUri(new Uri(pathInPackage, UriKind.Relative));
                        PackagePart packagePartDocument = package.CreatePart(partUriDocument,"", CompressionOption.Maximum);
                        using (FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read))
                        {
                            fileStream.CopyTo(packagePartDocument.GetStream());
                        }
                    }
                }
                result = true;
            }
            catch (Exception e)
            {
                throw new Exception("Error zipping folder " + folderName, e);
            }

            return result;
        }

 /// <summary>
        /// Compress a file into a ZIP archive as the container store
        /// </summary>
        /// <param name="fileName">The file to compress</param>
        /// <param name="compressedFileName">The archive file</param>
        /// <param name="overrideExisting">override existing file</param>
        /// <returns></returns>
        static bool PackageFile(string fileName, string compressedFileName, bool overrideExisting)
        {
            bool result = false;

            if (!File.Exists(fileName))
            {
                return result;
            }

            if (!overrideExisting && File.Exists(compressedFileName))
            {
                return result;
            }

            try
            {
                Uri partUriDocument = PackUriHelper.CreatePartUri(new Uri(Path.GetFileName(fileName), UriKind.Relative));

                using (Package package = Package.Open(compressedFileName, FileMode.OpenOrCreate))
                {
                    if (package.PartExists(partUriDocument))
                    {
                        package.DeletePart(partUriDocument);
                    } 

                    PackagePart packagePartDocument = package.CreatePart(partUriDocument, "", CompressionOption.Maximum);
                    using (FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read))
                    {
                        fileStream.CopyTo(packagePartDocument.GetStream());
                    }
                }
                result = true;
            }
            catch (Exception e)
            {
                throw new Exception("Error zipping file " + fileName, e);
            }

            return result;
        }

}       、zip文件解压

Code/// <summary>
        /// Extract a container Zip. NOTE: container must be created as Open Packaging Conventions (OPC) specification
        /// </summary>
        /// <param name="folderName">The folder to extract the package to</param>
        /// <param name="compressedFileName">The package file</param>
        /// <param name="overrideExisting">override existing files</param>
        /// <returns></returns>
        static bool UncompressFile(string folderName, string compressedFileName, bool overrideExisting)
        {
            bool result = false;
            try
            {
                if (!File.Exists(compressedFileName))
                {
                    return result;
                }

                DirectoryInfo directoryInfo = new DirectoryInfo(folderName);
                if (!directoryInfo.Exists)
                    directoryInfo.Create();

                using (Package package = Package.Open(compressedFileName, FileMode.Open, FileAccess.Read))
                {
                    foreach (PackagePart packagePart in package.GetParts())
                    {
                        ExtractPart(packagePart, folderName, overrideExisting);
                    }
                }

                result = true;
            }
            catch (Exception e)
            {
                throw new Exception("Error unzipping file " + compressedFileName, e);
            }

            return result;
        }

        static void ExtractPart(PackagePart packagePart, string targetDirectory, bool overrideExisting)
        {
            string stringPart = targetDirectory + HttpUtility.UrlDecode(packagePart.Uri.ToString()).Replace('\\', '/');

            if (!Directory.Exists(Path.GetDirectoryName(stringPart)))
                Directory.CreateDirectory(Path.GetDirectoryName(stringPart));

            if (!overrideExisting && File.Exists(stringPart))
                return;
            using (FileStream fileStream = new FileStream(stringPart, FileMode.Create))
            {
                packagePart.GetStream().CopyTo(fileStream);
            }
        }

原文网址：http://blog.csdn.net/fhzh520/article/details/1491900