winform http post

 public  string HttpPost()
        {
 
            HttpWebRequest webrequest =
                (HttpWebRequest)HttpWebRequest.Create("接口地址");
            webrequest.Method = "POST";
 
            webrequest.ContentType = "application/x-www-form-urlencoded"; //无关的请求头在本文中都省略掉了
 
            webrequest.Headers.Add("Access-Token", "Sinopec-Station");
 
            string postData = “json串” ;
 
            byte[] postdatabyte = Encoding.UTF8.GetBytes(postData);
            webrequest.ContentLength = postdatabyte.Length;
            Stream stream = webrequest.GetRequestStream();
            stream.Write(postdatabyte, 0, postdatabyte.Length);
            stream.Close();
 
            HttpWebResponse response = (HttpWebResponse)webrequest.GetResponse();
            Stream myResponseStream = response.GetResponseStream();
            //StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));
            StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));
            //StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("gb2312")); 
            string retString = myStreamReader.ReadToEnd();
            myStreamReader.Close();
            myResponseStream.Close();
            return retString;
        }
        
        post方法调用接口获取json文件内容
        public string PostFunction()
        {
            string serviceAddress = ""接口地址"";
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(serviceAddress);
            request.Headers.Add("Access-Token", "Sinopec-Station");
            request.Method = "POST";
            request.ContentType = "application/json";
            //request.CookieContainer = cookie; //cookie信息由CookieContainer自行维护
            using (StreamWriter dataStream = new StreamWriter(request.GetRequestStream()))
            {
                dataStream.Write(“json串”);
                dataStream.Close();
            }
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            string encoding = response.ContentEncoding;
            if (encoding == null || encoding.Length < 1)
            {
                encoding = "UTF-8"; //默认编码  
            }
            StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding(encoding));
            return reader.ReadToEnd();
 
        }
//已经用
 static CookieContainer cookie = new CookieContainer();
        public static string doHttpPost(string Url, string postDataStr)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
            request.Method = "POST";
            //request.ContentType = "application/json";
            //request.Accept = "application/json";
            request.ContentType = "application/json";
 
            //request.ContentLength = Encoding.UTF8.GetByteCount(postDataStr);
            request.CookieContainer = cookie;
            Stream myRequestStream = request.GetRequestStream();
            StreamWriter myStreamWriter = new StreamWriter(myRequestStream, Encoding.GetEncoding("gb2312"));
            myStreamWriter.Write(postDataStr);
            myStreamWriter.Close();
 
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
 
            response.Cookies = cookie.GetCookies(response.ResponseUri);
            Stream myResponseStream = response.GetResponseStream();
            StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));
            string retString = myStreamReader.ReadToEnd();
            myStreamReader.Close();
            myResponseStream.Close();
            return retString;
        }