无法读取未定义的SignalR Hub的属性'chatHub'

Question

我正在尝试学习信号器,这个错误我已经成立了.

无法读取未定义的属性'chatHub'.

$(document).ready(function () {
        var chat = $.connection.chatHub;
        $.connection.hub.start();
 });

和hub文件是:

namespace TestSignalR.Web.Hubs
{
public class ChatHub : Microsoft.AspNet.SignalR.Hub
{
    public void Send(string msg)
    {
        ChatData chat = new ChatData();
        chat.Msg = msg;
        chat.UserName = HttpContext.Current.User.Identity.Name;
        chat.Date = "? at " + DateTime.Now.ToString("hh:mm tt");
        Clients.All.broadCastMessage(chat);
    }
}
}

Answer 1

可能在<HEAD>文档中缺少这一行:

<script src="/signalr/hubs" type="text/javascript"></script>

检查你也有

 <script src="/Scripts/jquery.signalR-1.0.0.js"></script>

并使用Fiddler或Chrome开发者工具检查两个文件是否正在加载,并且/ hubs文件包含您希望它包含在集线器定义方面的内容.

Answer 2

由于MVC如何尝试提供帮助并呈现jquery包,我似乎总是遇到这个问题.然后,当您尝试在视图中添加signalr时,它将失败,因为您必须事先添加jquery,但然后MVC包再次加载jquery.这会混淆它似乎并导致错误.您可能会在主布局页面中包含此部分:

@Scripts.Render("~/bundles/jquery")
@RenderSection("scripts", required: false)

因此,如果您将脚本添加到脚本部分,它应该让信号器开心并且工作正常.

@section scripts {
    <!--Reference the SignalR library. -->
    <script src="Scripts/jquery.signalR-2.0.2.min.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>
}