使用淘宝接口查询手机号码归属地的方法

 private string gain(string Telnum)
        {
            string url = "https://tcc.taobao.com/cc/json/mobile_tel_segment.htm?tel=" + Telnum;
            System.Net.HttpWebRequest request = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(url);
            System.Net.HttpWebResponse response = (System.Net.HttpWebResponse)request.GetResponse();
            System.IO.Stream responseStream = response.GetResponseStream();
            System.IO.StreamReader sr = new System.IO.StreamReader(responseStream, System.Text.Encoding.GetEncoding("gbk"));
            string responseText = sr.ReadToEnd();
            sr.Close();
            sr.Dispose();
            responseStream.Close();
            string jsonData = responseText;
            if (jsonData != null && !"".Equals(jsonData))
            {
                jsonData = jsonData.Substring(jsonData.IndexOf("{"), (jsonData.IndexOf("}")) - (jsonData.IndexOf("{")) + 1);
            }
            return GainJsonMy(jsonData);

        }
        public struct JsonClass
        {
            public string mts { get; set; }  //属性的名字，必须与json格式字符串中的"key"值一样。
            public string province { get; set; }
            public string catName { get; set; }
            public string telString { get; set; }  //属性的名字，必须与json格式字符串中的"key"值一样。
            public string areaVid { get; set; }
            public string ispVid { get; set; }
            public string carrier { get; set; }
        }
        public string GainJsonMy(String str)