GET

public static string GetJsonStr(string webApi)
        {
            string serviceAddress = webApi;
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(serviceAddress);
            request.Method = "GET";
            request.ContentType = "application/json;charset=UTF-8";
            //request.ContentType = "application/text";
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            Stream myResponseStream = response.GetResponseStream();
            StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.UTF8);
            string retString = myStreamReader.ReadToEnd();
            return retString;
        }
            =============================

POST

public static string PostJsonStr(string webApi, string data)
        {
            WebRequest request = WebRequest.Create(webApi);
            request.Method = "Post";
            request.ContentType = "application/json;charset=utf-8";
            //request.ContentLength = data.Length;
            StreamWriter sw = new StreamWriter(request.GetRequestStream());
            request.Timeout = 1000*60*2;//超时时间
            sw.Write(data);
            sw.Flush();
            WebResponse response = request.GetResponse();
           
            Stream s = response.GetResponseStream();
            StreamReader sr = new StreamReader(s, Encoding.GetEncoding("utf-8"));
            string readStr = (sr.ReadToEnd());
            return readStr;
        }