SignalR ASP.NET 跨域连接问题

Question

我正在尝试实现here 中提到的 ASP.NET SignalR 应用程序。

我已经实现了here 中提到的客户端。对于客户端，我使用的是没有生成代理的代码。

客户端和服务器在同一域中时成功连接，但在托管跨域时无法通信。虽然上面文章中提到的跨域代码已经实现了。由于我的客户端和服务器托管在 Azure 中，Azure 中是否有需要启用跨域通信的设置，或者我还缺少其他什么？

这是我得到的错误：

请求的资源上不存在“Access-Control-Allow-Origin”标头。因此不允许 Origin 访问。响应的 HTTP 状态代码为 500。

我的创业班是：

public void Configuration(IAppBuilder app)
    {
        //app.UseCors(CorsOptions.AllowAll);

        // Any connection or hub wire up and configuration should go here
        //app.MapSignalR();
        // Branch the pipeline here for requests that start with "/signalr"
        app.Map("/signalr", map =>
        {
            // Setup the CORS middleware to run before SignalR.
            // By default this will allow all origins. You can 
            // configure the set of origins and/or http verbs by
            // providing a cors options with a different policy.
            map.UseCors(CorsOptions.AllowAll);
            var hubConfiguration = new HubConfiguration
            {
                // You can enable JSONP by uncommenting line below.
                // JSONP requests are insecure but some older browsers (and some
                // versions of IE) require JSONP to work cross domain
                // EnableJSONP = true
            };
            // Run the SignalR pipeline. We're not using MapSignalR
            // since this branch already runs under the "/signalr"
            // path.
            map.RunSignalR(hubConfiguration);
        });

    }

而客户端代码是：`

        $(function (){
        var ChatServerUrl ="http://chatserverurl.net/home/";
        var ChatUrl = ChatServerUrl + "signalr";

        var connection = $.hubConnection(ChatUrl, { useDefaultPath: false });

        connection.logging = true;
        var chatHubProxy = connection.createHubProxy('chatHub');

        chatHubProxy.on('addNewMessageToPage', function (name, message) {

            console.log("AddNewMessageToPage Function!");

            // Add the message to the page.
            $('#discussion').append('<li><strong>' + htmlEncode(name)
                + '</strong>: ' + htmlEncode(message) + '</li>');
        });

        // Get the user name and store it to prepend to messages.
        $('#displayname').val(prompt('Enter your name:', ''));
        // Set initial focus to message input box.
        $('#message').focus();
        // Start the connection.
        //connection.start({ withCredentials : false }).done(function () {
        connection.start({ withCredentials: true }).done(function () {
            $('#sendmessage').click(function () {
                // Call the Send method on the hub.
                chatHubProxy.invoke('Send', $('#displayname').val(), $('#message').val());
                // Clear text box and reset focus for next comment.
                $('#message').val('').focus();
            });

            console.log("SignalR Connected!");
        });
    });`

Answer 1

请根据以下链接建议尝试此操作

https://docs.microsoft.com/en-us/aspnet/signalr/overview/guide-to-the-api/hubs-api-guide-javascript-client