c#字符串压缩与解压缩

public class Compression
     {
         /// <summary>
         /// 对字符串进行压缩
         /// </summary>
         /// <param name="str">待压缩的字符串</param>
         /// <returns>压缩后的字符串</returns>
          public static string CompressString(string str)
         {   
             string compressString = "";
             byte[] compressBeforeByte = Encoding.GetEncoding("UTF-8").GetBytes(str);
             byte[] compressAfterByte=Compress(compressBeforeByte);
             //compressString = Encoding.GetEncoding("UTF-8").GetString(compressAfterByte);
             compressString = Convert.ToBase64String(compressAfterByte);
             return compressString;
         }
         /// <summary>
         /// 对字符串进行解压缩
         /// </summary>
         /// <param name="str">待解压缩的字符串</param>
         /// <returns>解压缩后的字符串</returns>
         public static string DecompressString(string str)
         {
             string compressString = "";
             //byte[] compressBeforeByte = Encoding.GetEncoding("UTF-8").GetBytes(str);
             byte[] compressBeforeByte = Convert.FromBase64String(str);
             byte[] compressAfterByte = Decompress(compressBeforeByte);
             compressString = Encoding.GetEncoding("UTF-8").GetString(compressAfterByte);
             return compressString;
         }
         /// <summary>
         /// 对文件进行压缩
         /// </summary>
         /// <param name="sourceFile">待压缩的文件名</param>
         /// <param name="destinationFile">压缩后的文件名</param>
         public static void CompressFile(string sourceFile, string destinationFile)
         {
             throw new Exception("The method or operation is not implemented.");
         }
         /// <summary>
         /// 对文件进行解压缩
         /// </summary>
         /// <param name="sourceFile">待解压缩的文件名</param>
         /// <param name="destinationFile">解压缩后的文件名</param>
         /// <returns></returns>
         public static void DecompressFile(string sourceFile, string destinationFile)
         {
             throw new Exception("The method or operation is not implemented.");
         }
         /// <summary>
         /// 对byte数组进行压缩
         /// </summary>
         /// <param name="data">待压缩的byte数组</param>
         /// <returns>压缩后的byte数组</returns>
         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);
             }
         }
     }