SignalR 2.0 CORS Chrome禁用Web安全性奇怪的行为

我正在努力让CORS与SignalR 2.0.0一起工作 - 我知道有很多关于它的SO帖子,我一直在仔细研究它们.

我在Chrome中使用已禁用的网络安全功能进行测试时遇到了一个问题,希望有人可以解释.

我有两个独立的MVC5站点(单独的解决方案)在IIS Express(不同的端口)上运行.其中一个是主机服务器,它安装了SignalR.该Startup.cs主机看起来是这样的:

public void Configuration(IAppBuilder app)
        {
            app.Map("/signalr", map =>
            {
                map.UseCors(CorsOptions.AllowAll);
                var hubConfiguration = new HubConfiguration
                {
                   // EnableJSONP = true                    
                   // EnableDetailedErrors = true                                     
                };
                map.RunSignalR(hubConfiguration);
            });
        }

我只用一个方法在主机上有一个集线器.另一个MVC5站点是客户端,它具有以下JavaScript:

jQuery的1.10.2.min.js

jquery.signalR-2.0.0.min.js

主机 MVC站点上对〜/ signalr/hubs JavaScript的引用

它调用的JS是以下(非常标准):

$.connection.hub.logging = true;
var chat = $.connection.chatHub;

    chat.client.broadcastMessage = function (name, message) {
        var encodedName = $('
').text(name).html();
        var encodedMsg = $('
').text(message).html();
        $('#discussion').append('
' + encodedName
            + ':  ' + encodedMsg + '
');
    };
    $('#displayname').val(prompt('Enter your name:', ''));
    $('#message').focus();

    $.connection.hub.url = 'http://localhost:60601/signalr'; // <-- pointing to the host MVC5 site
    $.connection.hub.start().done(function () {
        console.log("Connected, transport = " + $.connection.hub.transport.name);
        $('#sendmessage').click(function () {
            chat.server.send($('#displayname').val(), $('#message').val());
            $('#message').val('').focus();
        });
    }).fail(function (data) {
        console.log('[Hub Start FAILED]' + data);
    });

编辑发布日志

当我使用上面的代码时,我的主机站点上没有错误.在客户端站点上,我在Chrome DevTools控制台中收到以下错误:

[18:06:41 GMT-0600 (Central Standard Time)] SignalR: Auto detected cross domain url. 
[18:06:41 GMT-0600 (Central Standard Time)] SignalR: Client subscribed to hub 'chathub'.
[18:06:41 GMT-0600 (Central Standard Time)] SignalR: Negotiating with 'http://localhost:60601/signalr/negotiate?connectionData=%5B%7B%22name%22%3A%22chathub%22%7D%5D&clientProtocol=1.3'.
MLHttpRequest cannot load http://localhost:60601/signalr/negotiate?connectionData=%5B%7B%22name%22%3A%22chathub%22%7D%5D&clientProtocol=1.3&_=1386201997462. The 'Access-Control-Allow-Origin' header contains the invalid value 'http://localhost:50709, *'. Origin 'http://localhost:50709' is therefore not allowed access.
SignalR error: Error: Error during negotiation request.
[18:06:41 GMT-0600 (Central Standard Time)] SignalR: Stopping connection.

如果我通过添加参数来改变客户端javascript中集线器的启动$.connection.hub.start({ jsonp: true, transport: 'webSockets' })(如果我没有指定webSockets作为传输,那么SignalR成功使用longpolling传输),那么我得到以下错误日志.

客户端(Chrome DevTools控制台)

[18:06:41 GMT-0600 (Central Standard Time)] SignalR: Auto detected cross domain url. 
[18:06:41 GMT-0600 (Central Standard Time)] SignalR: Client subscribed to hub 'chathub'.
[18:12:16 GMT-0600 (Central Standard Time)] SignalR: Negotiating with 'http://localhost:60601/signalr/negotiate?connectionData=%5B%7B%22name%22%3A%22chathub%22%7D%5D&clientProtocol=1.3'
[18:12:17 GMT-0600 (Central Standard Time)] SignalR: Connecting to websocket endpoint 'ws://localhost:60601/signalr/connect?transport=webSockets&connectionToken=GzcGbVs35BV0AFtJ2%2BJQqEYlQfW6ejf6CJ8QI73zfG8OsonD0LIzDmtzNBWM6jSHiD0ptuStjmyOKTpszMFJOgVZoBLuYN08TYx1WUbdNqKDLRZ35Vozmk666%2F7x3rjgowmXhTjX0pVlx8nDY%2FWrpA%3D%3D&connectionData=%5B%7B%22name%22%3A%22chathub%22%7D%5D&tid=4'
[18:12:17 GMT-0600 (Central Standard Time)] SignalR: Websocket opened.
[18:12:22 GMT-0600 (Central Standard Time)] SignalR: webSockets timed out when trying to connect.
[18:12:22 GMT-0600 (Central Standard Time)] SignalR: Closing the Websocket.
SignalR error: Error: No transport could be initialized successfully. Try specifying a different transport or none at all for auto initialization.
[18:12:22 GMT-0600 (Central Standard Time)] SignalR: Stopping connection.
[18:12:22 GMT-0600 (Central Standard Time)] SignalR: Fired ajax abort async = true. 

和主机端(在VS2013输出窗口中):

SignalR.Transports.TransportHeartBeat Information: 0 : Connection 3e856309-8396-481e-8d32-b4085a93985f is New.
SignalR.Transports.WebSocketTransport Information: 0 : CloseSocket(3e856309-8396-481e-8d32-b4085a93985f)
SignalR.Transports.TransportHeartBeat Verbose: 0 : 3e856309-8396-481e-8d32-b4085a93985f is dead
SignalR.Transports.WebSocketTransport Information: 0 : Abort(3e856309-8396-481e-8d32-b4085a93985f)
SignalR.Transports.TransportHeartBeat Information: 0 : Removing connection 3e856309-8396-481e-8d32-b4085a93985f
SignalR.Transports.WebSocketTransport Information: 0 : End(3e856309-8396-481e-8d32-b4085a93985f)
SignalR.Transports.WebSocketTransport Verbose: 0 : DrainWrites(3e856309-8396-481e-8d32-b4085a93985f)
SignalR.Transports.WebSocketTransport Information: 0 : CompleteRequest (3e856309-8396-481e-8d32-b4085a93985f)

问题

我在Chrome禁用网络安全模式下启动主机网站,而客户端网站通常在Chrome中启动,我仍然收到CORS错误,连接被删除.

我在Chrome禁用网络安全模式启动客户端网站,主机网站通常在Chrome中启动,我遇到没有CORS问题,连接效果很好.

(如果两个网站都在Chrome禁用的网络安全模式下运行,那么效果很好,但这并不奇怪)

问题

当主机的安全性被禁用而客户端没有安全时,我希望不会遇到任何CORS问题 - 而不是相反.为什么会这样？