c#的post问题

在鼠标点击事件中调用服务器的接口，获取到本机mac地址，通过接口传递给服务器

CookieContainer cc = new CookieContainer();
string url = "服务器http接口";
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)";
request.KeepAlive = true;
request.CookieContainer = cc;
string date = "MAC=xxxxxxx";
request.ContentLength = date.Length;
StreamWriter writer = new StreamWriter(request.GetRequestStream(), Encoding.ASCII);
writer.Write(date);
writer.Flush();