SignalR集线器未从客户端连接，甚至未显示任何错误

Question

Included  Scripts version 2.2.3 based on a version of signalR packages.

<script src="Scripts/jquery.signalR-2.2.3.min.js"></script>
<script src="Scripts/jquery.signalR-2.2.3.js"></script>
<script src="~/signalr/hubs"></script>

通过HTML页面中的脚本从客户端连接集线器，代码如下所述

var chatProxy = $.connection.schoolAppHub;           
        $.connection.hub.start().done(function ()
        {       
          $('#btnSend').click(function ()
            {               
              chatProxy.server.broadCastMessage($("#spnName").text(), $("#txtMsg").val());
              $('#txtMsg').val('').focus();
            })
        })

集线器类代码也在下面注明

public class SchoolAppHub : Hub
{
    public void BroadCastMessage(String msgFrom, String msg)
    {
        Clients.All.receiveMessage(msgFrom, msg);
    }
}