SignalR: Error during negotiation request: undefined

问题

I've been trying to get a javascript signal-r client working against a self-hosted owin server. And am running into this issue. I've tried both proxies and no proxy methods both with the same result of the and error "SignalR: Error during negotiation request: undefined".

I've been able to get the cross-domain sample to run without any issues and cannot figure out what I am doing wrong, anyone have any ideas?

The browser console gets logs an attempt to negotiate then I get the failure.

Server/Hub

namespace SignalROwinHost
{
    class Program
    {
        static void Main(string[] args)
        {
            string url = "http://localhost:9000/";
            using (WebApplication.Start<Startup>(url))
            {
                Console.WriteLine("Server running on {0}", url);
                Console.ReadLine();
            }
        }

        public class Startup
        {
            public void Configuration(IAppBuilder app)
            {
                app.MapHubs();
            }

        }

        public class ChatHub : Hub
        {
            public void Send(string message)
            {
                Clients.All.send(message);
            }
        }
    }
}

Javascript(no-proxy):

<script type="text/javascript">
    $(function () {
        var connection = $.hubConnection('http://localhost:9000');
        var chat = connection.createHubProxy('chatHub');
        chat.on('send', function (message) {
            $('#chat').html($('#chat').html() + "\r\n" + message);
        });
        connection.logging = true;
        connection.start().done(function () {
            alert("Connection Complete");
            $('#sendBtn').click(function () {
                chat.invoke('send', $('#message').val());
            });
        }).fail(function (param) { alert(param); });
    });
</script>

Javascript (proxy):

<script src="http://localhost:9000/signalr/hubs" type="text/javascript"></script>
      <script type="text/javascript">
        $(function () {
            var chat = $.connection.chatHub;
            chat.client.send = function (message) {
                alert(message);
            };

            $.connection.hub.logging = true;

            $.connection.hub.url = "http://localhost:9000/signalr";

            $.connection.hub.start()
                .done(function (param) {
                    chat.server.send("Connected");
                })
                .fail(function (param) {
                    alert("Could not Connect: " + param);
                });
        });

  </script>

回答1:

If you are using SignalR 1.0.0 (which you should since it is now officially released), you need to change your call to MapHubs to enable cross-domain requests. This is assuming your website is not being served from localhost:9000. I'm guessing it isn't since you are passing in the url to $.hubConnection.

app.MapHubs(new HubConfiguration { EnableCrossDomain = true });

Before the final release of 1.0.0, CORS was enabled by default.

来源：https://stackoverflow.com/questions/14990789/signalr-error-during-negotiation-request-undefined