/// <summary>        /// MD5加密        /// </summary>        /// <param name="str"></param>        /// <param name="code"></param>        /// <returns></returns>        public static string MD5(string str, int code)        {            if (code == 16)            {                return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(str, "MD5").ToLower().Substring(8, 16);            }            else            {                return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(str, "MD5").ToLower();            }        }