用post请求方式实现对地图服务的基本操作

ArcGIS Server REST API 中的很多操作都可以用以下方式实现，具体参数的设置请查看其中的详细说明

  public List<string> getGeometry(string CZAH, string url)
        {
            url += "/query";//query url
            string postString = "where=CZAH='" + CZAH + "'";//where
            //postString += "text=04CH88131210000004";
            postString += "&" + "returnGeometry=true";//returnGeometry
            postString += "&" + "f=json";//json
            string result = getPostData(postString, url);
            List<string> list = new List<string>();
            var result1 = JsonConvert.DeserializeObject<dynamic>(result);//添加Newtonsoft.Json类库并引用;
            var list1 = result1.features as IEnumerable<dynamic>;
            dynamic[] jsonfea = list1.ToArray();
            for (int i = 0; i < jsonfea.Length; i++)
            {
                list.Add(jsonfea[i].geometry.ToString());
            }
            return list;
        }

        /// <summary>
        /// 获取post后的返回值
        /// </summary>
        /// <param name="postString">POST String</param>
        /// <param name="url">Post URL</param>
        /// <returns></returns>
        public string getPostData(string postString, string url)
        {
            string result = "";
            try
            {
                byte[] postData = Encoding.UTF8.GetBytes(postString);
                WebClient webClient = new WebClient();
                string method = "POST";
                //POST Header
                webClient.Headers.Add("Content-Type", "application/x-www-form-urlencoded");
                //webClient.Headers.Add("Cache-Control", "no-cache");
                //同步提交请求，并返回数据
                byte[] responseData = webClient.UploadData(url, method, postData);//得到返回字符流  
                result = Encoding.UTF8.GetString(responseData);//解码
            }
            catch (Exception)
            {
                throw;
            }
            return result;
        }