HttpWebRequest怎样设置http头

Question

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);

request.ContentType = "text/xml";

request.Timeout = 90000;
//request.Headers.Set("Platform", "10");
request.Headers.Add("Platform", "10");

无论是set 或者 add，在服务端　Request.Headers["Platform"]　都取不到值，求解？

Answer 1

找到原因了，因为使用了写入请求数据的流，所以会丢失http头