var wc = new WebClient { BaseAddress = "http://csdk.zzwhxx.com:8002/submitsms.aspx", Encoding = Encoding.GetEncoding("GBK") }; var param = new NameValueCollection { {"accountname", "sdkwhyouzheng"}, {"accountpwd", "336726"}, {"mobilecodes", message.Destination}, {"msgcontent", message.Body} }; wc.QueryString = param; var returncode = wc.DownloadString("");