SignalR客户端功能未被调用

时间：2013-04-04 14:47:57

标签： asp.net-mvc signalr

概述

我遇到的问题是让我的SignalR服务器/集线器在我的SignalR客户端上调用javascript函数。

我尝试了什么

  • 我已经阅读了更多教程，并查看了很多关于这应该如何工作的例子（包括官方文档），这几乎是荒谬的。
  • 除了核心功能之外，我已经尝试过评论。
  • 我确保服务器和客户端功能不一样且拼写正确。
  • 我也开启了登录，但Firebug控制台中没有出现任何错误。

Enviornment

有问题的SignalR代码已在ASP.net MVC4项目中使用VB.net与MySQL和Entity framework v5实现。我正在使用IISExpress在Visual Studio 2012中的本地开发计算机上调试系统。

代码段

global.asax.vb： 

Sub Application_Start()

    MiniProfilerEF.Initialize()

    AreaRegistration.RegisterAllAreas()

    ' Register the default hubs route: ~/signalr
    RouteTable.Routes.MapHubs()

    WebApiConfig.Register(GlobalConfiguration.Configuration)
    FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters)
    RouteConfig.RegisterRoutes(RouteTable.Routes)
    BundleConfig.RegisterBundles(BundleTable.Bundles)
    AuthConfig.RegisterAuth()

    ' Register custom view
    ViewEngines.Engines.Add(New CustomViewEngine())

End Sub

SignalR初始化javascript： 

$(function () {

    // Proxy created on the fly
    var notification = $.connection.notificationHub;
    //$.connection.notificationHub.logging = true;

    // Declare functions that can be run on the client by the server
    notification.client.sendNotification = onAddNotification;

    // Testing code only
    $("#testButton").click(function () {
        // Run test function on server
        notification.server.runTest();
    });

    // Map the onConnect and onDisconnect functions
    notification.client.connected = function () { };
    notification.client.disconnected = function () { };

    //$.connection.hub.start();
    $.connection.hub.start(function () {
        alert("Notification system connected");
    });
});

// Process a newly received notification from the server
function onAddNotification(message) {

    // Convert the passed json message back into an object
    var obj = JSON.parse(message);

    var parsedDate = new Date(parseInt(obj.Timestamp.substr(6)));

    // Update the notification list
    $('#notifications').prepend('<li>' + obj.Message + ' at ' + dateFormat(parsedDate, "default") + '</li>');

    // Update the new notification count
    var count = document.getElementById("notification_count")
    if (count.textContent) {
        //W3C DOM
        count.textContent = obj.Count;
    } else if (anchor.innerText) {
        //Microsoft DOM
        count.innerText = obj.Count;
    }
    //document.getElementById("notification_count").innerHTML = obj.Count + '<i class="splashy-comment"></i>';

    // Show a brief notification message
    $.sticky(obj.Message, { autoclose: 2000, position: "top-right", type: "st-info" });

};

集线器类： 

Public Class NotificationHub
Inherits Hub

ReadOnly Group As String = "Notification"

Public Function RunTest()
    Dim testMessage As New SignalR_Notification_Message

    testMessage.Count = 3
    testMessage.Message = "Some test message"
    testMessage.Timestamp = Now

    Call Notify(testMessage, "joebloggs")
End Function

Public Overrides Function OnConnected() As Task

    Dim db As New MyEntities
    Dim userName As String = Context.User.Identity.Name
    Dim connectionID = Context.ConnectionId

    Dim conn As SignalR_Connection

    ' Attempt to find a retrieve a connection entry with the same Connection ID
    conn = db.SignalR_Connection.Where(Function(s) s.Connection_ID = connectionID).FirstOrDefault

    ' If the connection does not already exist, add it
    If IsNothing(conn) Then
        conn = New SignalR_Connection

        ' Create the new connection entry
        conn.Connection_ID = connectionID
        conn.Username = userName
        conn.Group = Group

        ' Attempt to save the new connection entry
        Try
            db.SignalR_Connection.Add(conn)
            db.SaveChanges()
        Catch ex As Exception
            Dim a As String = ""
            a = ""
        End Try
    End If

    Return MyBase.OnConnected()
End Function

Public Overrides Function OnDisconnected() As Task

    Dim db As New MyEntities
    Dim userName As String = Context.User.Identity.Name
    Dim connectionId As String = Context.ConnectionId

    Dim conn As SignalR_Connection

    ' Attempt to find a retrieve the connection entry
    conn = db.SignalR_Connection.Where(Function(s) s.Connection_ID = connectionId And s.Username = userName).FirstOrDefault

    ' Attempt to remove the connection entry
    Try
        db.SignalR_Connection.Remove(conn)
        db.SaveChanges()
    Catch ex As Exception
        Dim a As String = ""
        a = ""
    End Try

    Return MyBase.OnDisconnected()
End Function

''' <summary>
''' Send the notification to the client
''' </summary>
Public Sub Notify(Message As SignalR_Notification_Message, Username As String)

    Dim ConnectionIDs As List(Of String)
    Dim Serializer As New JavaScriptSerializer()
    Dim json As String

    ' Attempt to convert the object into json before sending
    Try
        json = Serializer.Serialize(Message)
    Catch ex As Exception
        Exit Sub
    End Try

    ' Get the connection id's this message must go to
    ConnectionIDs = GetUsersConnectionID(Username)

    If Not IsNothing(ConnectionIDs) Then
        ' Send the message to all connection ID's
        For Each ConnectionID In ConnectionIDs
            Clients.Client(ConnectionID).sendNotification(json)
        Next
    End If

End Sub

''' <summary>
''' Retrieve a list of connection ID's for the current user
''' </summary>
Public Function GetUsersConnectionID(Username As String) As List(Of String)

    Dim db As New MyEntities

    ' Attempt to find a retrieve the connection entries
    Return db.SignalR_Connection.AsNoTracking.Where(Function(s) s.Username = Username).Select(Function(s) s.Connection_ID).ToList

End Function

End Class

HTML（部分视图）： 

@ModelType Geo_sight.NotificationWindowModel

<div class="modal hide fade" id="myNotifications">
<div class="modal-header">
    <button class="close" data-dismiss="modal">×</button>
    <h3>Notifications</h3>
</div>
<div class="modal-body">
    <ul class="unstyled" id="notifications">
        @For Each Notification In Model.Notifications
            @<li>@Html.Raw(Notification.Text)</li>
        Next
    </ul>
</div>
<div class="modal-footer">
    <a href="javascript:void(0)" class="btn" id="testButton">Send test</a>
</div>

问题

在 onAddNotification 函数的第一行设置断点：

  

var obj = JSON.parse（message）;

每当调用Hub中的 Notify 函数时，几乎从不调用客户端函数！

其他有用位

  1. 连接肯定是成功的，因为我可以在Firebug中看到连接长轮询。
  2. 我的用户连接已在 onConnected 和 GetUsersConnectionID 功能中成功保存并从我的数据库中检索。
  3. 在几十次和几十次尝试从服务器运行客户端功能（使用 testButton 来启动集线器上的通知调用）时，它运行的次数不超过3次-4倍，这两次我都没能重复过。
  4. 在该函数运行的非常罕见且随机的情况下，它已经完成了它应该做的事情，并且我已经能够在客户端中使用断点暂停执行该函数。

  5. 我已经检查了我的〜/ signalr / hubs 脚本，客户端功能定义下没有列出任何内容，但是是服务器上的内容（见下文）。它是否正确？我想客户端功能应该在这里？

    proxies.notificationHub = this.createHubProxy('notificationHub'); 
proxies.notificationHub.client = { };
proxies.notificationHub.server = {
    getUsersConnectionID: function (Username) {
        return proxies.notificationHub.invoke.apply(proxies.notificationHub, $.merge(["GetUsersConnectionID"], $.makeArray(arguments)));
     },

    notify: function (Message, Username) {
        return proxies.notificationHub.invoke.apply(proxies.notificationHub, $.merge(["Notify"], $.makeArray(arguments)));
     },

    runTest: function () {
        return proxies.notificationHub.invoke.apply(proxies.notificationHub, $.merge(["RunTest"], $.makeArray(arguments)));
     }
};

return proxies;

    6. 更新2013-04-04

    通过稍微调试，我可以让客户端运行但完全随机且非常偶然地只需在前一个signalR发送呼叫结束后几秒钟再次按下我的测试按钮。

    以下是Firebug控制台的一个示例... Firebug console

    更新2013-04-05

    随着越来越多的测试和调试，我遇到了客户端功能何时执行且未调用的特性......

    从我之前的更新中可以看出，SignalR选择使用长轮询，超时时间约为35秒。

    对客户端函数进行了多次进一步的重复调用后，似乎只有在长轮询生命的大约前10秒内进行的调用才能到达客户端并成功运行该函数。在此期间之后发出的电话似乎没有通过。

    我想这意味着我的代码是合理的，但为什么会发生这种情况？

    SignalR常见问题解答

    我也在这里发现了类似问题：SignalR Wiki FAQ's

    我使用的是Windows 7 Professional，但我没有使用IIS（我正在使用IIS Express），所以这可能是同样的问题吗？

0 个答案:

没有答案
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