字符串和BCD码转换

 private string BCDToString(byte bts)
        {
            try
            {
                string bs = (bts >> 4).ToString() + (((byte)(bts << 4)) >> 4).ToString();
                return bs;
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

 private byte StringToBCD(string str)
        {
            int x = int.Parse(str.Substring(0, 1));
            int y = int.Parse(str.Substring(1, 1));
            byte xx = Convert.ToByte(x);
            byte yy = Convert.ToByte(y);
            byte by = Convert.ToByte(((byte)xx << 4) + ((byte)yy));
            return by;
        }