public IHandler Negotiate(IRequest request, Func<byte[], Task> sendAction) { var path = new PathBuilder(request.Path).Build(); var route = _routeResolver.Resolve(path); if (route.Equals(Route.Empty)) throw new HandshakeException(HttpStatusCode.NotFound); var webSocketHandler = route.Handler(); var version = request.GetWebSocketVersion(); var handler = _protocolSelector.Select(version, m => webSocketHandler.OnMessage(m), () => webSocketHandler.OnClose(), b => webSocketHandler.OnBinary(b), b => webSocketHandler.OnPing(b), b => webSocketHandler.OnPong(b), ex => webSocketHandler.OnError(ex)); var routeParameters = _routeParametersBuilder.Build(route.Path, path); var queryParameters = _queryParametersBuilder.Build(path); var subProtocol = _subProtocolNegotiator.Negotiate(_hostConfiguration.SupportedSubProtocols, request.GetWebSocketProtocols()); webSocketHandler.Query = queryParameters; webSocketHandler.Route = routeParameters; webSocketHandler.Context = request.ToContext(subProtocol); webSocketHandler.SendAction = (message, frameType) => { switch (frameType) { case FrameType.Binary: sendAction(handler.FrameBinary(message)); break; case FrameType.Ping: sendAction(handler.FramePing(message)); break; case FrameType.Pong: sendAction(handler.FramePong(message)); break; case FrameType.Text: sendAction(handler.FrameText(message)); break; case FrameType.Close: sendAction(handler.FrameClose(WebSocketStatusCode.NormalClosure)); break; } }; var requestKey = request.Headers["Sec-WebSocket-Key"]; var response = new WebSocketAcceptResponse(requestKey, subProtocol); sendAction(response.ToBytes()).ContinueWith(t => webSocketHandler.OnOpen()); return handler; }