C# Hex编码和解码

/// 从字符串转换到16进制表示的字符串
       /// 编码,如"utf-8","gb2312" 
       /// 是否每字符用逗号分隔 
       public static string ToHex(string s, string charset, bool fenge)
       {
           if ((s.Length % 2) != 0)
           {
               s += " ";//空格
               //throw new ArgumentException("s is not valid chinese string!");
           }
           System.Text.Encoding chs = System.Text.Encoding.GetEncoding(charset);
           byte[] bytes = chs.GetBytes(s);
           string str = "";
           for (int i = 0; i < bytes.Length; i++)
           {
               str += string.Format("{0:X}", bytes[i]);
               if (fenge && (i != bytes.Length - 1))
               {
                   str += string.Format("{0}", ",");
               }
           }
           return str.ToLower();
       }
 
       /// 从16进制转换成utf编码的字符串
       /// 编码,如"utf-8","gb2312" 
       public static string UnHex(string hex, string charset)
       {
           if (hex == null)
               throw new ArgumentNullException("hex");
           hex = hex.Replace(",", "");
           hex = hex.Replace("\n", "");
           hex = hex.Replace("\\", "");
           hex = hex.Replace(" ", "");
           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");
               }
           }
           System.Text.Encoding chs = System.Text.Encoding.GetEncoding(charset);
           return chs.GetString(bytes);
       }