HttpListener下读取request body

public static string GetRequestPostData(HttpListenerRequest request)
        {
            if (!request.HasEntityBody)
            {
                return null;
            }
            using (System.IO.Stream body = request.InputStream) // here we have data
            {
                using (System.IO.StreamReader reader = new System.IO.StreamReader(body, request.ContentEncoding))
                {
                    return reader.ReadToEnd();
                }
            }
        }