汉字与16进制互转

 public static string GetHexFromChs(string s)
        {
            System.Text.Encoding chs = System.Text.Encoding.GetEncoding("gb2312");

            byte[] bytes = chs.GetBytes(s);

            string str = "";

            for (int i = 0; i < bytes.Length; i++)
            {
                str += string.Format("{0:X}", bytes[i]);
            }

            return str;
        }

        public static string GetChsFromHex(string hex)
        {
            if (hex == null)
                throw new ArgumentNullException("hex");
            if (hex.Length % 2 != 0)
            {
                hex += "20";//空格
                //throw new ArgumentException("hex is not a valid number!", "hex");
            }
            // 需要将 hex 转换成 byte 数组。
            byte[] bytes = new byte[hex.Length / 2];

            for (int i = 0; i < bytes.Length; i++)
            {
                try
                {
                    // 每两个字符是一个 byte。
                    bytes[i] = byte.Parse(hex.Substring(i * 2, 2),
                        System.Globalization.NumberStyles.HexNumber);
                }
                catch
                {
                    // Rethrow an exception with custom message.
                    throw new ArgumentException("hex is not a valid hex number!", "hex");
                }
            }

            // 获得 GB2312，Chinese Simplified。
            System.Text.Encoding chs = System.Text.Encoding.GetEncoding("gb2312");

            return chs.GetString(bytes);
        }