HttpWebRequest 只发送 Get 请求，不发送 POST

im 尝试使用 HttpWebRequest 发送 POST 请求，小提琴手向我显示我正在发送 GET？任何帮助将不胜感激，因为我能够看到我做错了什么。

法典：

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(LOGIN_API_BASE_URL);
        string postString = string.Format("api_email={0}&api_password={1}", EMAIL, PASSWORD);
        ASCIIEncoding encoding = new ASCIIEncoding();
        byte[] data = encoding.GetBytes(postString);
        CookieContainer cookies = new CookieContainer();
        request.CookieContainer = cookies;
        //request.AllowWriteStreamBuffering = true;
        request.Method = "POST";
        request.ContentType = "application/x-www-form-urlencoded";
        request.ContentLength = data.Length;
        request.Timeout = i_timeout;
        //request.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.1) Gecko/2008070208 Firefox/3.0.1";
        //request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
        //request.Referer = "https://accounts.craigslist.org";
        using (Stream writer  = request.GetRequestStream())
        {
            writer.Write(data, 0, data.Length);
            //writer.Close();
        }
        StreamReader responseReader = new StreamReader(request.GetResponse().GetResponseStream());
        string responseData = responseReader.ReadToEnd();
        responseReader.Close();
        request.GetResponse().Close();