C# HttpDirect

private HttpListener _httpListener;
private HttpTunnelClient(ushort listenPort, Uri serverUri, NetworkCredential credential, IPEndPoint remoteEndPoint = null, SocksProxyType? runType = null)
        {
_httpListener = new HttpListener();
                _httpListener.Prefixes.Add(string.Format("http://*:{0}/", listenPort));
                _httpListener.Start();
                _httpListener.BeginGetContext(this.GetContextCallback, null);
}

private void GetContextCallback(IAsyncResult ar)
        {
            if (_httpListener == null)
            {
                return;
            }
            _httpListener.BeginGetContext(this.GetContextCallback, null);

            var context = _httpListener.EndGetContext(ar);
            this.DirectHttp(context);
        }

        private void DirectHttp(HttpListenerContext context)
        {
            var Request = context.Request;
            var Response = context.Response;
            string destUri = Request.RawUrl;
            try
            {
                var tunnel = this.CreateTunnel(ClientNull, TunnelCommand.HttpDirect);
                tunnel.Headers[xHttpHandler.AgentDirect] = destUri;
                tunnel.Headers[xHttpHandler.AgentCommand] = ((int)TunnelCommand.HttpDirect).ToString();
                tunnel.Form.Remove(xHttpHandler.AgentCommand);
                //tunnel.SetProxy(xHttpHandler.GoAgent);
                using (var tResponse = tunnel.GetResponseWith(new HttpRequestWrapper(Request)))
                {
                    Response.StatusCode = (int)tResponse.StatusCode;
                    Response.StatusDescription = tResponse.StatusDescription;
                    Response.KeepAlive = tResponse.Headers[HttpResponseHeader.Connection] != "close";
                    if (tResponse.ContentLength >= 0)
                    {
                        Response.ContentLength64 = tResponse.ContentLength;
                    }
                    Response.ContentType = tResponse.ContentType;
                    foreach (string header in HttpRequestWrapper.SystemHeaders)
                    {
                        tResponse.Headers.Remove(header);
                    }
                    Response.Headers.Add(tResponse.Headers);

                    var tStream = tResponse.GetResponseStream();
                    tStream.FixedCopyTo(Response.OutputStream);
                }
                this.OutWrite("{0} \"{1} {2}\" {3}\t{4}bytes.", Request.LocalEndPoint, Request.HttpMethod, destUri,
                    Response.StatusCode, Response.ContentLength64);
                //如果写入未完成（异常等情况）就调用Close()则会抛“在写入所有字节之前不能关闭流”异常。
                Response.Close();
            }
            catch (WebException ex)
            {
                TunnelExceptionHandler.Handle(ex, string.Format("DirectHttp{0}={1}", Request.HttpMethod, destUri));
            }
            catch (Exception ex)
            {
                TunnelExceptionHandler.Handle(ex, string.Format("DirectHttp{0}={1}", Request.HttpMethod, destUri));
            }
        }

private void Direct2GoAgent(HttpContext context, Uri destUri)
        {
            context.Server.ScriptTimeout = Timeout;
            HttpRequest Request = context.Request;
            HttpResponse Response = context.Response;
            Request.Headers.Remove(HttpRequestHeader.Authorization.ToString());
            Request.Headers.Remove(AgentSock);
            Request.Headers.Remove(AgentDirect);
            Request.Headers.Remove(AgentCommand);

            var client = new HttpClient(destUri);
            client.SetRequest(destUri);
            client.SetProxy(GoAgent);
            try
            {
                using (var cResponse = client.GetResponseWith(new System.Web.HttpRequestWrapper(Request)))
                {
                    Response.StatusCode = (int)cResponse.StatusCode;
                    Response.StatusDescription = cResponse.StatusDescription;
                    Response.ContentType = cResponse.ContentType;
                    Response.Headers.Add(cResponse.Headers);

                    var cStream = cResponse.GetResponseStream();
                    cStream.FixedCopyTo(Response.OutputStream, (int)cResponse.ContentLength);
                    if (Response.IsClientConnected)
                    {
                        Response.Flush();
                    }
                }
            }
            catch (WebException ex)
            {
                TunnelExceptionHandler.Handle(ex, string.Format("Direct2GoAgent={0}", destUri));
            }
            catch (Exception ex)
            {
                TunnelExceptionHandler.Handle(ex, string.Format("Direct2GoAgent={0}", destUri));
            }
        }