string result = "sms&stat=100&message=发送成功";        string d = HttpUtility.ParseQueryString(result).Get("stat");        string dd = HttpUtility.ParseQueryString(result).Get("message");        string ddd = HttpUtility.ParseQueryString(result).Get("sms");        NameValueCollection qscoll = HttpUtility.ParseQueryString(result);        qscoll.Add("a", "nihao");        string ss = qscoll.Get("a");        string aaa = qscoll.ToString();//aaa的结果sms&stat=100&message=%u53d1%u9001%u6210%u529f&a=nihao