C#如何将十六进制数字符串转byte[]？

代码：

        /// <summary>
        /// 16进制原码字符串转字节数组
        /// </summary>
        /// <param name="hexString">"AABBCC"或"AA BB CC"格式的字符串</param>
        /// <returns></returns>
        public static byte[] ConvertHexStringToBytes(string hexString)
        {
            hexString = hexString.Replace(" ", "");
            if (hexString.Length %  != )
            {
                throw new ArgumentException("参数长度不正确");
            }

            byte[] returnBytes = new byte[hexString.Length / ];
            for (int i = ; i < returnBytes.Length; i++)
            {
                returnBytes[i] = Convert.ToByte(hexString.Substring(i * , ), );
            }

            return returnBytes;
        }