HttpWebRequest req = HttpWebRequest.Create("服务地址");//参数是服务地址
req.Method = "POST";//或get..
//如果你有文本要发送
Stream stream = req.GetRequestStream();
//写stream我就不说了
stream.Close();
HttpWebResponse res = req.GetResponse();
Stream resultStream = res.GetResponseStream();
byte[] buffer = new byte[resultStream.Length];
resultStream.Read(buffer, 0, buffer.Length);
String result = System.Text.Encoding.UTF8.GetString(buffer);//具体的编码按你的需求来