asp.net C#实现解压缩文件的方法

本文实例讲述了asp.net c#实现解压缩文件的方法。一共给大家介绍了三段代码，一个是简单的解压缩单个zip文件，后一个可以解压批量的大量的但需要调用icsharpcode.sharpziplib.dll类了，最后一个比较实例可压缩也可以解压缩了分享给大家供大家参考。具体如下：

解压缩单个文件：

using system.io;
using system.io.compression;
string sourcefile=@"d:2.zip";
string destinationfile=@"d:1.txt";
        private const long buffer_size = 20480;
            // make sure the source file is there
            if (file.exists ( sourcefile ))
            {
            filestream sourcestream = null;
            filestream destinationstream = null;
            gzipstream decompressedstream = null;
            byte[] quartetbuffer = null;
            try
            {
                // read in the compressed source stream
                sourcestream = new filestream ( sourcefile, filemode.open );
                // create a compression stream pointing to the destiantion stream
                decompressedstream = new deflatestream ( sourcestream, compressionmode.decompress, true );
                // read the footer to determine the length of the destiantion file
                quartetbuffer = new byte[4];
                int position = (int)sourcestream.length - 4;
                sourcestream.position = position;
                sourcestream.read ( quartetbuffer, 0, 4 );
                sourcestream.position = 0;
                int checklength = bitconverter.toint32 ( quartetbuffer, 0 );
                byte[] buffer = new byte[checklength + 100];
                int offset = 0;
                int total = 0;
                // read the compressed data into the buffer
                while ( true )
                {
                    int bytesread = decompressedstream.read ( buffer, offset, 100 );
                    if ( bytesread == 0 )
                        break;
                    offset += bytesread;
                    total += bytesread;
                }
                // now write everything to the destination file
                destinationstream = new filestream ( destinationfile, filemode.create );
                destinationstream.write ( buffer, 0, total );
                // and flush everyhting to clean out the buffer
                destinationstream.flush ( );
            }
            catch ( applicationexception ex )
            {
                console.writeline(ex.message, "解压文件时发生错误：");
            }
            finally
            {
                // make sure we allways close all streams
                if ( sourcestream != null )
                    sourcestream.close ( );
                if ( decompressedstream != null )
                    decompressedstream.close ( );
                if ( destinationstream != null )
                    destinationstream.close ( );
            }
}

批量解压缩(这需要调用一个解压缩类库。。 icsharpcode.sharpziplib.dll)

using system;
using system.io;
using system.collections.generic;
using system.text;
using icsharpcode.sharpziplib.zip;
namespace ziplib
{
    /// <summary>
    /// 解压缩类
    /// </summary>
   public static class zip
    {
        /// <summary>
        /// 解压zip文件包
        /// </summary>
        /// <param name="strzipfile">zip文件路径</param>
        /// <param name="strdir">解压后的文件目录路径</param>
        /// <returns>是否解压成功</returns>
        public static bool unzipfiles(string strzipfile, string strdir)
        {
            //判断zip文件是否存在
            if (file.exists(strzipfile))
            {
                //判断目录是否存在
                bool bunzipdir = false;
                //判断是否需要创建目录
                if (!directory.exists(strdir))
                    bunzipdir = (directory.createdirectory(strdir) != null);
                else
                    bunzipdir = true;
                //如果解压目录存在
                if (bunzipdir)
                {
                    //获得zip数据流
                    zipinputstream zipstream = new zipinputstream(file.openread(strzipfile));
                    if (zipstream != null)
                    {
                        zipentry zipentry = null;
                        while ((zipentry = zipstream.getnextentry()) != null)
                        {
                            string strunzipfile = strdir + "//" + zipentry.name;
                            string strfilename = path.getfilename(strunzipfile);
                            string strdirname = path.getdirectoryname(strunzipfile);
                            //是否为解压目录
                            if (!string.isnullorempty(strdirname))
                                directory.createdirectory(strdirname);
                            //是否为解压文件
                            if (!string.isnullorempty(strfilename))
                            {
                                //解压文件
                                filestream unzipfilestream = new filestream(strunzipfile, filemode.create);
                                if (unzipfilestream != null)
                                {
                                    byte[] buf = new byte[2048];
                                    int size = 0;
                                    while ((size = zipstream.read(buf, 0, 2048)) > 0)
                                        unzipfilestream.write(buf, 0, size);
                                    //关闭stream
                                    unzipfilestream.flush();
                                    unzipfilestream.close();
                                }
                            }
                        }
                        //关闭zip流
                        zipstream.close();
                        //返回值
                        return true;
                    }
                }
            }
            return false;
        }
    }
}

上面两个都是解压缩文件，下面我们把压缩与解压缩放在一个实例中。
最近要做一个项目涉及到c#中压缩与解压缩的问题的解决方法，大家分享。
这里主要解决文件夹包含文件夹的解压缩问题。

下载sharpziplib.dll，在http://www.icsharpcode.net/opensource/sharpziplib/download.aspx中有最新免费版本，“assemblies for .net 1.1, .net 2.0, .net cf 1.0, .net cf 2.0: download [297 kb] ”点击download可以下载，解压后里边有好多文件夹，因为不同的版本，我用的fw2.0。
或者点击此处本站下载。

引用sharpziplib.dll，在项目中点击项目右键-->添加引用-->浏览，找到要添加的dll-->确认

改写了文件压缩和解压缩的两个类，新建两个类名字为zipfloclass.cs,unzipfloclass.cs
源码如下

using system;
using system.data;
using system.configuration;
using system.web;
using system.web.security;
using system.web.ui;
using system.io;
using icsharpcode.sharpziplib.checksums;
using icsharpcode.sharpziplib.zip;
using icsharpcode.sharpziplib.gzip;
/// <summary>
/// zipfloclass 的摘要说明
/// </summary>
public class zipfloclass
{
    public void zipfile(string strfile, string strzip)
    {
        if (strfile[strfile.length - 1] != path.directoryseparatorchar)
            strfile += path.directoryseparatorchar;
        zipoutputstream s = new zipoutputstream(file.create(strzip));
        s.setlevel(6); // 0 - store only to 9 - means best compression
        zip(strfile, s, strfile);
        s.finish();
        s.close();
    }

    private void zip(string strfile, zipoutputstream s, string staticfile)
    {
        if (strfile[strfile.length - 1] != path.directoryseparatorchar) strfile += path.directoryseparatorchar;
        crc32 crc = new crc32();
        string[] filenames = directory.getfilesystementries(strfile);
        foreach (string file in filenames)
        {
            if (directory.exists(file))
            {
                zip(file, s, staticfile);
            }
            else // 否则直接压缩文件
            {
                //打开压缩文件
                filestream fs = file.openread(file);
                byte[] buffer = new byte[fs.length];
                fs.read(buffer, 0, buffer.length);
                string tempfile = file.substring(staticfile.lastindexof("\") + 1);
                zipentry entry = new zipentry(tempfile);
                entry.datetime = datetime.now;
                entry.size = fs.length;
                fs.close();
                crc.reset();
                crc.update(buffer);
                entry.crc = crc.value;
                s.putnextentry(entry);
                s.write(buffer, 0, buffer.length);
            }
        }
    }
}

using system;
using system.data;
using system.web;
using system.text;
using system.collections;
using system.io;
using system.diagnostics;
using system.runtime.serialization.formatters.binary;
using icsharpcode.sharpziplib.bzip2;
using icsharpcode.sharpziplib.zip;
using icsharpcode.sharpziplib.zip.compression;
using icsharpcode.sharpziplib.zip.compression.streams;
using icsharpcode.sharpziplib.gzip;
using icsharpcode.sharpziplib.checksums;

/// <summary>
/// unzipfloclass 的摘要说明
/// </summary>
public class unzipfloclass
{
    public string unzipfile(string targetfile, string filedir)
    {
        string rootfile = " ";
        try
        {
            //读取压缩文件(zip文件)，准备解压缩
            zipinputstream s = new zipinputstream(file.openread(targetfile.trim()));
            zipentry theentry;
            string path = filedir;                  
            //解压出来的文件保存的路径
            string rootdir = " ";                       
            //根目录下的第一个子文件夹的名称
            while ((theentry = s.getnextentry()) != null)
            {
                rootdir = path.getdirectoryname(theentry.name);                         
                //得到根目录下的第一级子文件夹的名称
                if (rootdir.indexof("\") >= 0)
                {
                    rootdir = rootdir.substring(0, rootdir.indexof("\") + 1);
                }
                string dir = path.getdirectoryname(theentry.name);                   
                //根目录下的第一级子文件夹的下的文件夹的名称
                string filename = path.getfilename(theentry.name);                   
                //根目录下的文件名称
                if (dir != " " )                                                       
                    //创建根目录下的子文件夹,不限制级别
                {
                    if (!directory.exists(filedir + "\" + dir))
                    {
                        path = filedir + "\" + dir;                                               
                        //在指定的路径创建文件夹
                        directory.createdirectory(path);
                    }
                }
                else if (dir == " " && filename != "")                                            
                    //根目录下的文件
                {
                    path = filedir;
                    rootfile = filename;
                }
                else if (dir != " " && filename != "")                                            
                    //根目录下的第一级子文件夹下的文件
                {
                    if (dir.indexof("\") > 0)                                                           
                        //指定文件保存的路径
                    {
                        path = filedir + "\" + dir;
                    }
                }
                if (dir == rootdir)                                                                                 
                    //判断是不是需要保存在根目录下的文件
                {
                    path = filedir + "\" + rootdir;
                }
                //以下为解压缩zip文件的基本步骤
                //基本思路就是遍历压缩文件里的所有文件，创建一个相同的文件。
                if (filename != string.empty)
                {
                    filestream streamwriter = file.create(path + "\" + filename);
                    int size = 2048;
                    byte[] data = new byte[2048];
                    while (true)
                    {
                        size = s.read(data, 0, data.length);
                        if (size > 0)
                        {
                            streamwriter.write(data, 0, size);
                        }
                        else
                        {
                            break;
                        }
                    }
                    streamwriter.close();
                }
            }
            s.close();
            return rootfile;
        }
        catch (exception ex)
        {
            return "1; " + ex.message;
        }
    }  
}

引用，新建一个页面，添加两个按钮，为按钮添加click事件
源码如下

protected void button1_click(object sender, eventargs e)
{
        string[] fileproperties = new string[2];
        fileproperties[0] = "d:\unzipped\";//待压缩文件目录
        fileproperties[1] = "d:\zip\a.zip";  //压缩后的目标文件
        zipfloclass zc = new zipfloclass();
        zc.zipfile(fileproperties[0], fileproperties[1]);
}
protected void button2_click(object sender, eventargs e)
{
        string[] fileproperties = new string[2];
        fileproperties[0] = "d:\zip\b.zip";//待解压的文件
        fileproperties[1] = "d:\unzipped\";//解压后放置的目标目录
        unzipfloclass unzc = new unzipfloclass();
        unzc.unzipfile(fileproperties[0], fileproperties[1]);
}

希望本文所述对大家的asp.net程序设计有所帮助。