private byte[] Compression(byte[] data, CompressionMode mode)        {            DeflateStream zip = null;            try            {                if (mode == CompressionMode.Compress)//压缩函数                {                    MemoryStream ms = new MemoryStream();                    zip = new DeflateStream(ms, mode, true);                    zip.Write(data, 0, data.Length);                    zip.Close();                    return ms.ToArray();                }                else//解压函数                {                    MemoryStream ms = new MemoryStream();                    ms.Write(data, 0, data.Length);                    ms.Flush();                    ms.Position = 0;                    zip = new DeflateStream(ms, mode, true);                    MemoryStream os = new MemoryStream();                    int SIZE = 1024*100;                    byte[] buf = new byte[SIZE];                    int l = 0;                    do                    {                        l = zip.Read(buf, 0, SIZE);                        if (l == 0) l = zip.Read(buf, 0, SIZE);                        os.Write(buf, 0, l);                    } while (l != 0);                    zip.Close();                    return os.ToArray();                }            }            catch            {                if (zip != null) zip.Close();                return null;            }            finally            {                if (zip != null) zip.Close();            }        }