C# 用SharpZipLib实现加密压缩、加密解压

SharpZipLib 是一个免费的Zip操作类库，可以利用它对 ZIP 等多种格式进行压缩与解压。下载网址：http://www.icsharpcode.net/OpenSource/SharpZipLib/Download.aspx。目前的版本为0.86。 

1、创建zip文件，并添加文件：

2、将文件夹压缩为文件

最后一个参数是使用正则表达式表示的过滤文件规则。CreateZip方法有3个重载版本，其中有目录过滤参数、文件过滤参数及用于指定是否进行子目录递归的一个bool类型的参数。

3、将文件添加到已有zip文件中

4、列出zip文件中文件

5、删除zip文件中的一个文件

 6、解压zip文件中文件到指定目录下

7、常用类

ZipInputStream、GZipInputStream用于解压缩Deflate、GZip格式流，ZipOutputStream、GZipOutputStream用于压缩Deflate、GZip格式流。
StreamUtil类包含了几个Stream处理辅助方法：
  1) Copy(Stream, Stream, Byte[])用于从一个Stream对象中复制数据到另一Stream对象。有多个重写。
  2) ReadFully(Stream, Byte [])用于从Stream对象中读取所有的byte数据。有多个重写。

代码如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Security.Cryptography;
using ICSharpCode.SharpZipLib.Checksums;
using ICSharpCode.SharpZipLib.Zip;

namespace XB.imp_exp
{
    class ZipClass
    {
        public void ZipFile(string FileToZip, string ZipedFile, int CompressionLevel, int BlockSize)
        {
            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 password)
        {
            string[] filenames = Directory.GetFiles(args[0]);

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

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

            s.Password = md5.encrypt(password);

            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);

                Array arr = file.Split('\\');
                string le = arr.GetValue(arr.Length - 1).ToString();
                ZipEntry entry = new ZipEntry(le);
                entry.DateTime = DateTime.Now;
                entry.Size = fs.Length;
                fs.Close();
                s.PutNextEntry(entry);
                s.Write(buffer, 0, buffer.Length);
            }
            s.Finish();
            s.Close();
        }
    }

    class UnZipClass
    {
        public void UnZip(string[] args, string password)
        {
            string directoryName = Path.GetDirectoryName(args[1]);
            using (FileStream fileStreamIn = new FileStream(args[0], FileMode.Open, FileAccess.Read))
            {
                using (ZipInputStream zipInStream = new ZipInputStream(fileStreamIn))
                {
                    zipInStream.Password = md5.encrypt(password);
                    ZipEntry entry = zipInStream.GetNextEntry();
                    do
                    {
                        using (FileStream fileStreamOut = new FileStream(directoryName + @"\" + entry.Name, FileMode.Create, FileAccess.Write))
                        {

                            int size = 2048;
                            byte[] buffer = new byte[2048];
                            do
                            {
                                size = zipInStream.Read(buffer, 0, buffer.Length);
                                fileStreamOut.Write(buffer, 0, size);
                            } while (size > 0);
                        }
                    } while ((entry = zipInStream.GetNextEntry()) != null);
                }
            }
        }
    }

    class md5
    {
        #region "MD5加密"
        /// <summary>
        ///32位 MD5加密
        /// </summary>
        /// <param name="str">加密字符</param>
        /// <returns></returns>
        public static string encrypt(string str)
        {
            string cl = str;
            string pwd = "";
            MD5 md5 = MD5.Create();
            byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(cl));
            for (int i = 0; i < s.Length; i++)
            {
                pwd = pwd + s[i].ToString("X");
            }
            return pwd;
        }
        #endregion
    }

}