C#PDU编码UCS2加密解密函数

原文地址:http://www.cnblogs.com/ycdx2001/archive/2011/04/24/2026468.html

       /// <summary>
       /// UCS2解码 
       /// </summary>
       /// <param name="src"> UCS2 源串 </param>
       /// <returns> 解码后的UTF-16BE字符串</returns>
       public static string DecodeUCS2(string src)
       {
           string decucs = src.Remove(src.IndexOf("/r"));
           string pstr = "^[0-9a-fA-F]+$";
           if (!Regex.IsMatch(decucs, pstr))
           {
               return "非法字符串无法解析！";
           }

           StringBuilder builer = new StringBuilder();

           for (int i = 0; i < decucs.Length; i += 4)
           {
               int unicode_nu = Int32.Parse(decucs.Substring(i, 4), System.Globalization.NumberStyles.HexNumber);
               builer.Append(string.Format("{0}", (char)unicode_nu));
           }

           return builer.ToString();
       }

        /// <summary>
        /// UCS2编码
        /// </summary>
        /// <param name="src"> UTF-16BE编码的源串</param>
        /// <returns>编码后的UCS2串 </returns>
        public static string EncodeUCS2(string src)
        {
            StringBuilder builer = new StringBuilder();
            builer.Append("000800");
            byte[] tmpSmsText = Encoding.Unicode.GetBytes(src);
            builer.Append(tmpSmsText.Length.ToString("X2")); //正文内容长度
            for (int i = 0; i < tmpSmsText.Length; i += 2) //高低字节对调 
            {
                builer.Append(tmpSmsText[i + 1].ToString("X2"));//("X2")转为16进制
                builer.Append(tmpSmsText[i].ToString("X2"));
            }
            builer = builer.Remove(0, 8);

            return builer.ToString();
        }