/// <summary>
 /// 压缩文件
 /// </summary>

using System;
using System.IO;

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

namespace Compression
{
 public class ZipClass
 {
 
  public void ZipFile(string FileToZip, string ZipedFile ,int CompressionLevel, int BlockSize)
  {
   //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]);
  
   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 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 = fs.Length;
    fs.Close();
   
    crc.Reset();
    crc.Update(buffer);
   
    entry.Crc  = crc.Value;
   
    s.PutNextEntry(entry);
   
    s.Write(buffer, 0, buffer.Length);
   
   }
  
   s.Finish();
   s.Close();
  }
 }
}

//现在再来看看解压文件类的源码

 /// <summary>
 /// 解压文件
 /// </summary>

using System;
using System.Text;
using System.Collections;
using System.IO;
using System.Diagnostics;
using System.Runtime.Serialization.Formatters.Binary;
using System.Data;

using ICSharpCode.SharpZipLib.BZip2;
using ICSharpCode.SharpZipLib.Zip;
using ICSharpCode.SharpZipLib.Zip.Compression;
using ICSharpCode.SharpZipLib.Zip.Compression.Streams;
using ICSharpCode.SharpZipLib.GZip;

namespace DeCompression
{
 public class UnZipClass
 {   
  public void UnZip(string[] args)
  {
   ZipInputStream s = new ZipInputStream(File.OpenRead(args[0]));
  
   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) 
    {