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用ASP.Net实现文件的在线压缩和解压缩

答案:

  我们经常会遇到批量上传的问题,也会遇到将某个目录下所有文件都上传到服务器上的问题。那么,如何解决此类问题呢?以前的技术一般采用ActiveX等方式,这里笔者采用SharpZlib来实现,听说VS2005已有压缩和解压缩的解决方案,笔者还没有时间用VS2005,所以就只好使用VS2003 + SharpZlib来解决问题了。

  1、首先从这里下载0.84版本的SharpZlib源码及示例码。
  2、下载下来之后你发现它没有VS2003的解决方案文件,没有关系。你可以自己建立,首先新建一个ZipUnzip的解决方案,然后,将上面经过解压缩之后的所有文件及目录COPY到你的解决方案所在的目录下。
  3、在VS2003解决方案资源管理器(一般是在右上方中部点的位置)中点击显示所有文件按钮,然后可以见到很多“虚”的图标、文件及文件夹等,可以一次选择它们,然后包含进项目中。
  4、编译,最好使用Release选项,编译完成之后你可以在\bin\Release\看到ZipUnzip.dll的类了。如果你编译时报错,说什么AssemblyKeyFile之类的,你可以使用强命名工具新建一个,也可以将AssemblyInfo.cs中[assembly: AssemblyKeyFile("。。。。。")]改成:[assembly: AssemblyKeyFile("")] (不推荐这样做)。
  5、新建一个WEBFORM项目,添加ZipUnzip.dll类的引用,然后添加如下文件及内容:

// ------------------------------------------
// 1. AttachmentUnZip.cs
// ------------------------------------------
using System;
using System.IO;
using ICSharpCode.SharpZipLib.Zip;
using ICSharpCode.SharpZipLib.GZip;
using ICSharpCode.SharpZipLib.BZip2;
using ICSharpCode.SharpZipLib.Checksums;
using ICSharpCode.SharpZipLib.Zip.Compression;
using ICSharpCode.SharpZipLib.Zip.Compression.Streams;

namespace WebZipUnzip
{
public class AttachmentUnZip
{
public AttachmentUnZip()
{
}
public static void UpZip(string zipFile)
{
string []FileProperties=new string[2];
FileProperties[0]=zipFile;//待解压的文件
FileProperties[1]=zipFile.Substring(0,zipFile.LastIndexOf("\\")+1);//解压后放置的目标目录
UnZipClass UnZc=new UnZipClass();
UnZc.UnZip(FileProperties);
}
}
}

// ---------------------------------------------
// 2. UnZipClass.cs
// ---------------------------------------------

using System;
using System.IO;
using ICSharpCode.SharpZipLib.Zip;
using ICSharpCode.SharpZipLib.GZip;
using ICSharpCode.SharpZipLib.BZip2;
using ICSharpCode.SharpZipLib.Checksums;
using ICSharpCode.SharpZipLib.Zip.Compression;
using ICSharpCode.SharpZipLib.Zip.Compression.Streams;

namespace WebZipUnzip
{
public class UnZipClass
{
/// <summary>
/// 解压文件
/// </summary>
/// <param name="args">包含要解压的文件名和要解压到的目录名数组</param>
public void UnZip(string[] args)
{
ZipInputStream s = new ZipInputStream(File.OpenRead(args[0]));
try
{
ZipEntry theEntry;
while ((theEntry = s.GetNextEntry()) != null)
{
string directoryName = Path.GetDirectoryName(args[1]);
string fileName = Path.GetFileName(theEntry.Name);

//生成解压目录
Directory.CreateDirectory(directoryName);

if (fileName != String.Empty)
{
//解压文件到指定的目录
FileStream streamWriter = File.Create(args[1]+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();
}
catch(Exception eu)
{
throw eu;
}
finally
{
s.Close();
}

}//end UnZip

public static bool UnZipFile(string file, string dir)
{
try
{
if (!Directory.Exists(dir))
Directory.CreateDirectory(dir);
string fileFullName = Path.Combine(dir,file);
ZipInputStream s = new ZipInputStream(File.OpenRead( fileFullName ));

ZipEntry theEntry;
while ((theEntry = s.GetNextEntry()) != null)
{
string directoryName = Path.GetDirectoryName(theEntry.Name);
string fileName = Path.GetFileName(theEntry.Name);

if (directoryName != String.Empty)
Directory.CreateDirectory( Path.Combine(dir, directoryName));

if (fileName != String.Empty)
{
FileStream streamWriter = File.Create( Path.Combine(dir,theEntry.Name) );
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 true;
}
catch (Exception)
{
throw;
}
}

}//end UnZipClass
}

// ----------------------------------------------
// 3. ZipClass.cs
// ----------------------------------------------
using System;
using System.IO;
using ICSharpCode.SharpZipLib.Zip;
using ICSharpCode.SharpZipLib.GZip;
using ICSharpCode.SharpZipLib.BZip2;
using ICSharpCode.SharpZipLib.Checksums;
using ICSharpCode.SharpZipLib.Zip.Compression;
using ICSharpCode.SharpZipLib.Zip.Compression.Streams;

namespace WebZipUnzip
{
/// <summary>
/// 压缩文件
/// </summary>
public class ZipClass
{
public void ZipFile(string FileToZip, string ZipedFile ,int CompressionLevel, int BlockSize,string password)
{
//如果文件没有找到,则报错
if (! System.IO.File.Exists(FileToZip))
{
throw new System.IO.FileNotFoundException("The specified file " + FileToZip + " could not be found. Zipping aborderd");
}

System.IO.FileStream StreamToZip = new System.IO.FileStream(FileToZip,System.IO.FileMode.Open , System.IO.FileAccess.Read);
System.IO.FileStream ZipFile = System.IO.File.Create(ZipedFile);
ZipOutputStream ZipStream = new ZipOutputStream(ZipFile);
ZipEntry ZipEntry = new ZipEntry("ZippedFile");
ZipStream.PutNextEntry(ZipEntry);
ZipStream.SetLevel(CompressionLevel);
byte[] buffer = new byte[BlockSize];
System.Int32 size =StreamToZip.Read(buffer,0,buffer.Length);
ZipStream.Write(buffer,0,size);
try
{
while (size < StreamToZip.Length)
{
int sizeRead =StreamToZip.Read(buffer,0,buffer.Length);
ZipStream.Write(buffer,0,sizeRead);
size += sizeRead;
}
}
catch(System.Exception ex)
{
throw ex;
}
ZipStream.Finish();
ZipStream.Close();
StreamToZip.Close();
}

public void ZipFileMain(string[] args)
{
//string[] filenames = Directory.GetFiles(args[0]);
string[] filenames = new string[]{args[0]};

Crc32 crc = new Crc32();
ZipOutputStream s = new ZipOutputStream(File.Create(args[1]));

s.SetLevel(6); // 0 - store only to 9 - means best compression

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, 0, buffer.Length);
ZipEntry entry = new ZipEntry(file);

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

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