如何终止 SignalR 连接？

Question

我正在使用 SignalR 在网站上传输数据。但是 SignalR 应该只能在一段时间内发送数据，如果超过了该时间段，则应该终止连接。

如果请求仍未完成且未完成，则停止函数 $.connection.hub.stop() 将被取消。但是无论发送多少数据，这个请求都应该被强制取消。

我如何杀死 SignalR-Connection？

Answer 1

您需要定义超时。在服务器上你可以设置 DisconnectTimeout，像这样：

GlobalHost.Configuration.DisconnectTimeout = TimeSpan.FromMinutes(30);

https://zzz.buzz/2016/05/11/setting-timeout-for-signalr-for-easier-debugging/

Answer 2

正如您在此 Microsoft Documentation about Timeout and keepalive settings 中看到的，您可以在选项中定义 DisconnectTimeout。

示例：

protected void Application_Start(object sender, EventArgs e)
{
    // Make long-polling connections wait a maximum of 110 seconds for a
    // response. When that time expires, trigger a timeout command and
    // make the client reconnect.
    GlobalHost.Configuration.ConnectionTimeout = TimeSpan.FromSeconds(110);

    // Wait a maximum of 30 seconds after a transport connection is lost
    // before raising the Disconnected event to terminate the SignalR connection.
    GlobalHost.Configuration.DisconnectTimeout = TimeSpan.FromSeconds(30);

    // For transports other than long polling, send a keepalive packet every
    // 10 seconds. 
    // This value must be no more than 1/3 of the DisconnectTimeout value.
    GlobalHost.Configuration.KeepAlive = TimeSpan.FromSeconds(10);

    RouteTable.Routes.MapHubs();
}

编辑：因为无论如何你都想终止来自客户端的连接，所以你正在谈论 CancellationToken 行为，但不幸的是，这在SignalR 如您所见 here and here，团队希望对 SignalR 这样做，但仍然没有相关消息。

Answer 3

更新编辑，请参阅下面的选项 3。 其他的都是靠超时，我贴了个强制断开。

如果您正在尝试强制断开连接——您可以获得已连接用户的列表并在服务器端调用 ForceLogOut 函数，我在代码项目的某处看到了这个，希望它有所帮助。如果您只想 forceLogout/kill 一些用户，只需循环并仅终止该连接。

服务器端

public class User
{
    public string Name { get; set; }
    public HashSet<string> ConnectionIds { get; set; }
}

public class ExtendedHub : Hub
{        
   private static readonly ConcurrentDictionary<string, User> ActiveUsers  = 
      new ConcurrentDictionary<string, User>(StringComparer.InvariantCultureIgnoreCase);
    public IEnumerable<string> GetConnectedUsers()
    {
        return ActiveUsers.Where(x => {

            lock (x.Value.ConnectionIds)
            {
                return !x.Value.ConnectionIds.Contains
                        (Context.ConnectionId, StringComparer.InvariantCultureIgnoreCase);
            }

        }).Select(x => x.Key);
    }           

    public void forceLogOut(string to)
    {
        User receiver;
        if (ActiveUsers.TryGetValue(to, out receiver))
        {
            IEnumerable<string> allReceivers;
            lock (receiver.ConnectionIds)
            {
                allReceivers = receiver.ConnectionIds.Concat(receiver.ConnectionIds);      
            }

            foreach (var cid in allReceivers)
            {
             // ***************** log out/KILL connection for whom ever your want here
                Clients.Client(cid).Signout();
            }
        }
    }
}

客户端

 // 1- Save your connection variable when you start it, and later on you can use it to stop.
var myHubProxy = $.connection.myHub 
// 2- Use it when you need to stop it, IF NOT YOU WILL GET AN ERROR
myHubProxy.client.stopClient = function() {
    $.connection.hub.stop();
};

// With a button for testing
$('#SomeButtonKillSignalr').click(function () {
            $.connection.hub.stop();                
        });

已更新选项 3：根据要求...其他解决方案依赖超时，但您也可以直接强制执行 通过自己处理连接

我打开了 SignalR 代码，在里面你可以看到 DisposeAndRemoveAsync 客户端连接的实际终止。

1- 您可以使用您的连接修改或调用 DisposeAndRemoveAsync。

2- 然后调用 RemoveConnection(connection.ConnectionId);

public async Task DisposeAndRemoveAsync(HttpConnectionContext connection)
        {
            try
            {
                // this will force it
                await connection.DisposeAsync();
            }
            catch (IOException ex)
            {
                _logger.ConnectionReset(connection.ConnectionId, ex);
            }
            catch (WebSocketException ex) when (ex.InnerException is IOException)
            {
                _logger.ConnectionReset(connection.ConnectionId, ex);
            }
            catch (Exception ex)
            {
                _logger.FailedDispose(connection.ConnectionId, ex);
            }
            finally
            {
                // Remove it from the list after disposal so that's it's easy to see
                // connections that might be in a hung state via the connections list
                RemoveConnection(connection.ConnectionId);
            }
        }

注意，完成后请自行清理。

Answer 4

请阅读 this 有关 Hub 生命周期事件的 Microsoft 文档。您可以更改这些设置的默认值，在 Global.asax 文件的 Application_Start 中设置它们。但是这样你就不能完全控制客户端。因此，您使用 javascript setTimeout 函数并在新用户 connect.it 可能 GlobalHost.Configuration.DisconnectTimeout 或您想要的任何时间传递时间表单服务器端。我用演示项目给出了一个完整的例子。实际上我在一个非常大的票务系统中使用这个逻辑来实时持有票。（请阅读所有内联评论）

型号：

public class MyModel
{
    public int Id { get; set; }

    public string Name { get; set; }


    public static string Send(MyModel my)
    {
        //Do Somthing           
        return $"Data Sending to {my.Name}...";
    }
    public static string Stop(string name)
    {
        //Do Somthing

        return $"ForceStop {name}.";
    }
    public static string Delete()
    {
        //Do Somthing

        return "Deleted";
    }
}

中心：

[HubName("myHub")]
public class MyHub : Hub
{
    int connectionTimeOut = 10;//sec

    [HubMethodName("connect")]
    public void Connect()
    {  
            //apply logic if any when user connected or reload page
            //set connection Time Out as you need
        connectionTimeOut= 10;// GlobalHost.Configuration.DisconnectTimeout

       Clients.Client(Context.ConnectionId).onNewUserConnected(connectionTimeOut);
    }
    [HubMethodName("startSendingServer")]
    public void StartSending(int id, string name)//pass anything you need
    {
        //apply logic if any when start sending data

        var my = new MyModel
        {
            Id = id,
            Name = name
        };
        var status = MyModel.Send(my);//example

        var result = new
        {
            status,
            name
        };

        Clients.Client(Context.ConnectionId).startSendingClient(result);

    }

    [HubMethodName("forceStopServer")]
    public void ForceStop(string name)//pass anything you need
    {
        //apply logic if any when force stop sending data
        var status = MyModel.Stop(name);
        Clients.Client(Context.ConnectionId).forceStopClint(status);
    }


    public override Task OnDisconnected(bool stopCalled)
    {

        //apply logic if any when connection Disconnected

        var status = MyModel.Delete();//example
        if (stopCalled)
        {
            //  status=String.Format("Client {0} explicitly closed the connection.", Context.ConnectionId)
            //your code here
        }
        else
        {
            // status=String.Format("Client {0} timed out .", Context.ConnectionId);
            //your code here
            //Clients.Client(Context.ConnectionId).onUserDisconnected(status);
        }

        return base.OnDisconnected(stopCalled);
    }


}

测试视图：

<div class="row">
    <div class="col-md-12">
        <h1> Status: <span id="hubStatus"></span></h1>
        <br />
        <h4> Countdown : <span id="counter"></span></h4>
        <br />

        <button id="btnHub" class="btn btn-primary btn-lg">Start Sending Data</button>
    </div>
</div>
@section scripts{
    <script src="~/Scripts/app/hub.js"></script>
}

hub.js:

var proxyTimer = null;
var sendTimeLimit = 1;//sec
var sessionTime = sendTimeLimit * 1000;

$(function () {
    var myProxy = $.connection.myHub;
    $.connection.hub.start().done(function () {
        registerServerEvents(myProxy);
    });

    clientMethods(myProxy);
});

function registerServerEvents(proxyHub) {
    proxyHub.server.connect();
    $(document).on("click", "#btnHub", function (e) {

        $("#hubStatus").html("Sending..");
        $("#btnHub").text("Count Down Start...");

        //Logic Before start sending data.
        var id = 1;
        var name = "AzR";        
        proxyHub.server.startSendingServer(id,name);

       // $.connection.hub.disconnected(function () {
      //  setTimeout(function () { $.connection.hub.start(); }, 5000); // Restart connection after 5 seconds.
       //});

        $.connection.hub.disconnected(function () {
            $("#hubStatus").html("Disconnected");// you can restart on here.     
            $("#btnHub").text("Stat Again after reload window");

        });

    });
}



function clientMethods(proxyHub) {

    //proxyHub.on('onConnected', function (sendTimeLimit) {
    //    sendTimeLimit = sendTimeLimit;
    //});

    proxyHub.on('onNewUserConnected', function (serverItem) {
        sendTimeLimit = serverItem;
        sessionTime = sendTimeLimit * 1000;
    });


    proxyHub.on('startSendingClient', function (serverItem) {

        //Logic after start sending data.
        var name = serverItem.name;
        var status = serverItem.status;
        $("#hubStatus").html(status);
        $("#counter").html(sendTimeLimit);
        timeCounter();
        startTimer(proxyHub, name );
    });

    proxyHub.on('forceStopClint', function (serverItem) {


        clearClintPendingTask(serverItem);//Logic before proxy stop.
        $("#btnHub").text("Force Stop...");
        $.connection.hub.stop();
    });

    proxyHub.on('onUserDisconnected', function (serverItem) {
        //Logic after proxy Disconnected (time out).
        $("#hubStatus").html(serverItem);
        $("#btnHub").text("Stat Again after reload window");
   });
}

//Logic before proxy stop.
function clearClintPendingTask(status) {
    //do all you need
    $("#hubStatus").html(status); 
    stopTimer();
}

function startTimer(proxyHub,data) {
    stopTimer();
    proxyTimer = setTimeout(function () {
        proxyHub.server.forceStopServer(data);
    }, sessionTime);
}

function stopTimer() {
    if (proxyTimer) {
        clearTimeout(proxyTimer);
        proxyTimer = null;
    }
}

function timeCounter() {
    var counter = sendTimeLimit;
    var interval = setInterval(function () {
        counter--;
        $("#counter").html(counter);
        if (counter == 0) {
            //Do something
            $("#counter").html("Countdown ended!");
            // Stop the counter
            clearInterval(interval);
        }
    }, 1000);
}

（已测试）

如何终止 SignalR 连接？

How can I kill a SignalR connection?

javascript

c#

asp.net-mvc

signalr