///解压缩目录中的所有zip文件
using System;
using System.IO;
using System.IO.Compression;
using System.Collections;
using System.Collections.Generic;
private const long BUFFER_SIZE = 20480;
class FolderUnzip
{
static void main(string[] args)
{
string sourcepath=@"D:temp";
Queue Folders = new Queue(new DirectoryInfo(sourcepath).GetFileSystemInfos());
string copytopath =@"E:tt";
copytopath = (copytopath.LastIndexOf(Path.DirectorySeparatorChar) == copytopath.Length - 1) ? copytopath : (copytopath+Path.DirectorySeparatorChar) + Path.GetFileName(sourcepath);
Directory.CreateDirectory(copytopath);
while (Folders.Count > 0)
{
    FileSystemInfo atom = Folders.Dequeue();
    FileInfo zipfile = atom as FileInfo;
    if (zipfile == null)
    {
        DirectoryInfo directory = atom as DirectoryInfo;
        Directory.CreateDirectory(directory.FullName.Replace(sourcepath,copytopath));
        foreach (FileSystemInfo nextatom in directory.GetFileSystemInfos())
            Folders.Enqueue(nextatom);
    }
    else
    {
        if (zipfile.Name.IndexOf(".zip") > -1)
        {
            string zipfilename = zipfile.FullName;
            string originalfilename = zipfilename.Replace(sourcepath,copytopath).Substring(0, (int)(zipfile.Length - 4));
            if (!File.Exists(originalfilename))
            {
                FileStream sourceStream = null;
                FileStream destinationStream = null;
                GZipStream decompressedStream = null;
                byte[] quartetBuffer = null;
                try
                {
                    // Read in the compressed source stream
                    sourceStream = new FileStream(zipfilename, FileMode.Open);

                    if(sourceStream.Length>4)
{
                    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;
                    }
                    destinationStream = new FileStream(originalfilename, FileMode.Create);
                    destinationStream.Write(buffer, 0, total);
                    destinationStream.Flush();
}
                }
                catch (ApplicationException)
                {
                    continue;
                }
                finally
                {
                    // Make sure we allways close all streams
                    if (sourceStream != null)  sourceStream.Close();
                    if (decompressedStream != null)  decompressedStream.Close();
                    if (destinationStream != null) destinationStream.Close();
                }
            }
        }
    }
}
}
}