C# crc16位校验和多个字节组成int

int num = Int32.Parse(byteDateLine[3].ToString("X2") + byteDateLine[4].ToString("X2"), System.Globalization.NumberStyles.HexNumber);//多个字节转int
//CRC校验
 public static bool CRCCalc(byte[] data)
        {
            try
            {
                if (Convert.ToInt32(data[0]) == 20 && Convert.ToInt32(data[1]) == 3 && Convert.ToInt32(data[2]) == 2)
                {
                    //计算并填写CRC校验码
                    byte[] crcbuf = new byte[data.Length - 2];
                    Buffer.BlockCopy(data, 0, crcbuf, 0, data.Length - 2);
                    int crc = 0xffff;
                    int len = crcbuf.Length;
                    for (int n = 0; n < len; n++)
                    {
                        byte i;
                        crc = crc ^ crcbuf[n];
                        for (i = 0; i < 8; i++)
                        {
                            int TT;
                            TT = crc & 1;
                            crc = crc >> 1;
                            crc = crc & 0x7fff;
                            if (TT == 1)
                            {
                                crc = crc ^ 0xa001;
                            }
                            crc = crc & 0xffff;
                        }

                    }
                    string[] redata = new string[2];
                    redata[1] = Convert.ToString((byte)((crc >> 8) & 0xff), 16).ToUpper();
                    redata[0] = Convert.ToString((byte)((crc & 0xff)), 16).ToUpper();
                    if (redata[0] == (data[data.Length - 2]).ToString("X2").ToUpper() && redata[1] == (data[data.Length - 1]).ToString("X2").ToUpper())
                    {
                        return true;
                    }
                    else
                    {
                        return false;
                    }
                }
                else
                {
                    return false;
                }
            }
            catch (Exception)
            {
                return false;
            }
        }