对文件和字符串压缩及解压缩类

    /// 

    /// 对文件和字符串压缩及解压缩类
    /// 
    public class GZip
    {
        /// 

        /// 对字符串进行压缩
        /// 
        /// 待压缩的字符串
        /// 压缩后的字符串
        public static string CompressString(string str)
        {
            string compressString = "";
            byte[] compressBeforeByte = Encoding.Default.GetBytes(str);
            byte[] compressAfterByte=GZip.Compress(compressBeforeByte);
            compressString = Encoding.Default.GetString(compressAfterByte);
            return compressString;
        }
        /// 

        /// 对字符串进行解压缩
        /// 
        /// 待解压缩的字符串
        /// 解压缩后的字符串
        public static string DecompressString(string str)
        {
            string compressString = "";
            byte[] compressBeforeByte = Encoding.Default.GetBytes(str);
            byte[] compressAfterByte = GZip.Decompress(compressBeforeByte);
            compressString = Encoding.Default.GetString(compressAfterByte);
            return compressString;
        }
        /// 

        /// 对文件进行压缩
        /// 
        /// 待压缩的文件名
        /// 压缩后的文件名
        public static void CompressFile(string sourceFile, string destinationFile)
        {
            throw new Exception("The method or operation is not implemented.");
        }
        /// 

        /// 对文件进行解压缩
        /// 
        /// 待解压缩的文件名
        /// 解压缩后的文件名
        /// 
        public static void DecompressFile(string sourceFile, string destinationFile)
        {
            throw new Exception("The method or operation is not implemented.");
        }
        /// 

        /// 对byte数组进行压缩
        /// 
        /// 待压缩的byte数组
        /// 压缩后的byte数组
        public static byte[] Compress(byte[] data)
        {
            try
            {
                MemoryStream ms = new MemoryStream();
                GZipStream zip = new GZipStream(ms, CompressionMode.Compress,true);
                zip.Write(data, 0, data.Length);
                zip.Close();
                byte[] buffer = new byte[ms.Length];
                ms.Position=0;
                ms.Read(buffer, 0, buffer.Length);
                ms.Close();
                return buffer;

            }
            catch (Exception e)
            {
                throw new Exception(e.Message);
            }
        }
        public static byte[] Decompress(byte[] data)
        {
            try
            {
                MemoryStream ms = new MemoryStream(data);
                GZipStream zip = new GZipStream(ms,CompressionMode.Decompress,true);
                MemoryStream msreader = new MemoryStream();
                byte[] buffer = new byte[0x1000];
                while (true)
                {
                    int reader=zip.Read(buffer, 0, buffer.Length);
                    if (reader <= 0)
                    {
                        break;
                    }
                    msreader.Write(buffer, 0, reader);                   
                }
                zip.Close();
                ms.Close();
                msreader.Position = 0;
                buffer = msreader.ToArray();
                msreader.Close();
                return buffer;
            }
            catch (Exception e)
            {
                throw new Exception(e.Message);
            }
        }
         

        /// 对目标文件夹进行压缩，将压缩结果保存为指定文件
        /// 
        /// 目标文件夹
        /// 压缩文件
        public static void Compress(string dirPath, string fileName)
        {
            ArrayList list = new ArrayList();
            foreach (string f in Directory.GetFiles(dirPath))
            {
                byte[] destBuffer = File.ReadAllBytes(f);
                SerializeFileInfo sfi = new SerializeFileInfo(f, destBuffer);
                list.Add(sfi);
            }
            IFormatter formatter = new BinaryFormatter();
            using (Stream s = new MemoryStream())
            {
                formatter.Serialize(s, list);
                s.Position = 0;
                CreateCompressFile(s, fileName);
            }
        }

         

        /// 对目标压缩文件解压缩，将内容解压缩到指定文件夹
        /// 
        /// 压缩文件
        /// 解压缩目录
        public static void DeCompress(string fileName, string dirPath)
        {
            using (Stream source = File.OpenRead(fileName))
            {
                using (Stream destination = new MemoryStream())
                {
                    using (GZipStream input = new GZipStream(source, CompressionMode.Decompress, true))
                    {
                        byte[] bytes = new byte[4096];
                        int n;
                        while ((n = input.Read(bytes, 0, bytes.Length)) != 0)
                        {
                            destination.Write(bytes, 0, n);
                        }
                    }
                    destination.Flush();
                    destination.Position = 0;
                    DeSerializeFiles(destination, dirPath);
                }
            }
        }

        private static void DeSerializeFiles(Stream s, string dirPath)
        {
            BinaryFormatter b = new BinaryFormatter();
            ArrayList list = (ArrayList)b.Deserialize(s);

            foreach (SerializeFileInfo f in list)
            {
                string newName = dirPath + Path.GetFileName(f.FileName);
                using (FileStream fs = new FileStream(newName, FileMode.Create, FileAccess.Write))
                {
                    fs.Write(f.FileBuffer, 0, f.FileBuffer.Length);
                    fs.Close();
                }
            }
        }

        private static void CreateCompressFile(Stream source, string destinationName)
        {
            using (Stream destination = new FileStream(destinationName, FileMode.Create, FileAccess.Write))
            {
                using (GZipStream output = new GZipStream(destination, CompressionMode.Compress))
                {
                    byte[] bytes = new byte[4096];
                    int n;
                    while ((n = source.Read(bytes, 0, bytes.Length)) != 0)
                    {
                        output.Write(bytes, 0, n);
                    }
                }
            }
        }

        [Serializable]
        class SerializeFileInfo
        {
            public SerializeFileInfo(string name, byte[] buffer)
            {
                fileName = name;
                fileBuffer = buffer;
            }

            string fileName;
            public string FileName
            {
                get
                {
                    return fileName;
                }
            }

            byte[] fileBuffer;
            public byte[] FileBuffer
            {
                get
                {
                    return fileBuffer;
                }
            }
        }
    }