C#模拟HTTP POST 请求

 /// 

        /// 获取accessToken
        /// 
        /// ID
        /// 密钥
        /// 
        static string GetQYAccessToken(string corpid, string corpsecret)
        {
            string getAccessTokenUrl = "https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid={0}&corpsecret={1}";
            string accessToken = "";

            string respText = "";

            //获取josn数据
            string url = string.Format(getAccessTokenUrl, corpid, corpsecret);

            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();

            using (Stream resStream = response.GetResponseStream())
            {
                StreamReader reader = new StreamReader(resStream, Encoding.Default);
                respText = reader.ReadToEnd();
                resStream.Close();
            }

            try
            {
                JavaScriptSerializer Jss = new JavaScriptSerializer();
                Dictionarystring, object> respDic = (Dictionarystring, object>)Jss.DeserializeObject(respText);

                //通过键access_token获取值
                accessToken = respDic["access_token"].ToString();
            }
            catch (Exception ex) { }

            return accessToken;
        }

/// 

        /// Post数据接口
        /// 
        /// 接口地址
        /// 提交json数据
        /// 编码方式
        /// 
        static string PostWebRequest(string postUrl, string paramData, Encoding dataEncode)
        {
            string ret = string.Empty;
            try
            {
                byte[] byteArray = dataEncode.GetBytes(paramData); //转化
                HttpWebRequest webReq = (HttpWebRequest)WebRequest.Create(new Uri(postUrl));
                webReq.Method = "POST";
                webReq.ContentType = "application/x-www-form-urlencoded";

                webReq.ContentLength = byteArray.Length;
                Stream newStream = webReq.GetRequestStream();
                newStream.Write(byteArray, 0, byteArray.Length);//写入参数
                newStream.Close();
                HttpWebResponse response = (HttpWebResponse)webReq.GetResponse();
                StreamReader sr = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
                ret = sr.ReadToEnd();
                sr.Close();
                response.Close();
                newStream.Close();
            }
            catch (Exception ex)
            {
                return ex.Message;
            }
            return ret;
        }