signalR : /signalr/hubs is not generated

问题:

I can get this tutorial to work in a new project, but not in my existing project.

My project is an ASP.Net MVC 4 web application with the following attribute in the web.config file:

<appSettings>
  <add key="webpages:Enabled" value="true"/>
</appSettings>

This is because my application is a Single-Page-Application, which uses AngularJS on the client side. The only page in my application is index.cshtml, to which I've added the relevant code for signalR:

 <!-- signalR chat -->
<script src="~/Scripts/jquery.signalR-1.0.0.js"></script>
<!--Reference the autogenerated SignalR hub script. -->
<script src="/signalr/hubs"></script>
<!--Add script to update the page and send messages.--> 
<script type="text/javascript">
    $(function () {
        // Declare a proxy to reference the hub. 
        var chat = $.connection.chatHub;
        // Create a function that the hub can call to broadcast messages.
        chat.client.broadcastMessage = function (name, message) {
            // Html encode display name and message. 
            var encodedName = $('<div />').text(name).html();
            var encodedMsg = $('<div />').text(message).html();
            // Add the message to the page. 
            $('#discussion').append('<li><strong>' + encodedName
                + '</strong>:&nbsp;&nbsp;' + encodedMsg + '</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.hub.start().done(function () {
            $('#sendmessage').click(function () {
                // Call the Send method on the hub. 
                chat.server.send($('#displayname').val(), $('#message').val());
                // Clear text box and reset focus for next comment. 
                $('#message').val('').focus();
            });
        });
    });
</script>

Then I've got the ChatHub.cs file:

public class ChatHub : Hub
{
    public void Send(string name, string message)
    {
        // Call the broadcastMessage method to update clients.
        Clients.All.broadcastMessage(name, message);
    }
}

And finally in the global.asax:

 protected void Application_Start()
    {
        RouteTable.Routes.MapHubs();
        BundleConfig.RegisterBundles(BundleTable.Bundles);
    }

When I run the application, the /signalr/hubs file is not generated. I get a 404 when requesting the file, and it crashes on the line:

 chat.client.broadcastMessage = function (name, message) { ....

because chat is null as the previous line did not find chatHub:

var chat = $.connection.chatHub;

Does anyone know what's wrong with my code ?

UPDATE

I have solved my problem by changing the line::

<script src="/signalr/hubs"></script>

to

<script src="~/signalr/hubs"></script>

回答1:

I have solved my problem by changing the line::

<script src="/signalr/hubs"></script>

to

<script src="~/signalr/hubs"></script>

回答2:

Also, the reason why /signalr/hubs are not generated is forget to Map SignalR in OWIN Startup Configuration.

public class Startup
{
   public void Configuration(IAppBuilder appBuilder){
         ...
         appBuilder.MapSignalR();
         ...
   }
 ...

回答3:

In my case, it was because my ChatHub class was not marked public.

回答4:

I had a similar problem where the hubs file wasn't being generated. It looks like the OP was following the steps here. The way I fixed the problem had to do with the jquery includes. The tutorial I linked below was written with jquery 1.6.4 and jquery-signalr version 2.1.0. When Visual Studio generated the Scripts folder for me, it used jquery version 1.10.2 and jquery-signalr version 2.0.2.

The way I fixed this was simply to edit the index.html file. Note that you can use Chrome's javascript console window Ctrl+Shift+J to see errors.

回答5:

I'll like to add that the signalR Readme file have some note about this issue. And also if your signalR page is in a PartialView some script should be place in the master page.

Please see http://go.microsoft.com/fwlink/?LinkId=272764 for more information on using SignalR.

Upgrading from 1.x to 2.0
-------------------------
Please see http://go.microsoft.com/fwlink/?LinkId=320578 for more information on how to 
upgrade your SignalR 1.x application to 2.0.

Mapping the Hubs connection
----------------------------
To enable SignalR in your application, create a class called Startup with the following:

using Microsoft.Owin;
using Owin;
using MyWebApplication;

namespace MyWebApplication
{
    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            app.MapSignalR();
        }
    }
} 

Getting Started
---------------
See http://www.asp.net/signalr/overview/getting-started for more information on how to get started.

Why does ~/signalr/hubs return 404 or Why do I get a JavaScript error: 'myhub is undefined'?
--------------------------------------------------------------------------------------------
This issue is generally due to a missing or invalid script reference to the auto-generated Hub JavaScript proxy at '~/signalr/hubs'.
Please make sure that the Hub route is registered before any other routes in your application.

In ASP.NET MVC 4 you can do the following:

      <script src="~/signalr/hubs"></script>

If you're writing an ASP.NET MVC 3 application, make sure that you are using Url.Content for your script references:

    <script src="@Url.Content("~/signalr/hubs")"></script>

If you're writing a regular ASP.NET application use ResolveClientUrl for your script references or register them via the ScriptManager 
using a app root relative path (starting with a '~/'):

    <script src='<%: ResolveClientUrl("~/signalr/hubs") %>'></script>

If the above still doesn't work, you may have an issue with routing and extensionless URLs. To fix this, ensure you have the latest 
patches installed for IIS and ASP.NET. 

回答6:

For me the solution was to reinstall all the packages and restore all the dependecies.

Open nuget powershell console and use this command.

Update-Package -Reinstall

回答7:

In my case i was missing :

        app.MapSignalR();

in public void Configuration(IAppBuilder app) function located in startup.cs