Question

我正在尝试从控制器方法向我的客户端方法发送数据，该方法在实例客户端断开连接时返回响应。

控制器 目前..

 public void SomeMethod(){
    IHubContext hubContext = GlobalHost.ConnectionManager.GetHubContext<MyHub>();

    while(true){
         hubContext.Clients.All.addNameValue(name,value);
    }
 }

我想要什么..

 bool someProperty = false
 public string SomeMethod(){
    IHubContext hubContext = GlobalHost.ConnectionManager.GetHubContext<MyHub>();

    while(true & (someProperty == false)){
         hubContext.Clients.All.addNameValue(name,value);
    }
    return "done";
 }

因为我们知道客户端断开了集线器覆盖的方法..

集线器

 public override Task OnDisconnected(bool stopCalled = true)
    {
        Console.WriteLine("Hub Disconnected: {0}\n", Context.ConnectionId);
        return (base.OnDisconnected(stopCalled));
    }

是否有任何方法可以从集线器外部跟踪控制器实例，以便可以完成这样的事情？

public override Task OnDisconnected(bool stopCalled = true)
    {
        SomeClass.someProperty = true;
        Console.WriteLine("Hub OnDisconnected {0}\n", Context.ConnectionId);
        return (base.OnDisconnected(stopCalled));
    }

当我们想要来回传输数据时，我们寻求使用信号R打开连接的能力，但能够知道客户端何时断开连接以便客户端可以继续执行操作。

Answer 1

如果您创建一个使用单例类来跟踪客户端的集线器，那么如果需要，您可以存储所有连接的客户端，以便在服务器重新联机时重新连接。客户端上确实没有断开事件，只有重新连接的事件。因此很难确定服务器是否已断开连接。我解决这个问题的方法是订阅connection.closed事件。对我来说，我尝试重新连接，失败，我通知用户并退出应用程序。有关保持跟踪客户端的单例方法的信息，我从这个链接开发了我的http://www.asp.net/signalr/overview/getting-started/tutorial-server-broadcast-with-signalr

       tcHubProxy(HubConnection hubConnection, StreamWriter writer)
    {
        mhubConn = hubConnection;
        mIHubProxy = hubConnection.CreateHubProxy("CentralHub");
        mWriter = writer;
        mWriter.AutoFlush = true;

        try
        {
            mhubConn.TraceLevel = TraceLevels.All;
            mhubConn.TraceWriter = mWriter;
            mhubConn.Closed += MhubConnOnClosed;
            mhubConn.Start().Wait();
            LogEvent(DateTime.Now, "Info", "Client Connected");
            mIHubProxy.On<List<User>>("updateFmds", GetUserFmds);
            connected = true;
        }
        catch (Exception e)
        {
            if (showMessage)
            {
                MessageBox.Show(
                    "There is currently no connection to the server, this application will close, if this issue persists check your network connection or contact support.",
                    "Connection Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                showMessage = false;
            } 
            connected = false;
            showMessage = false;
        }
    }

 public void MhubConnOnClosed()
    {
        LogEvent(DateTime.Now, "Info", "Client connection to communication hub, attempting to redirect.");
        try
        {
            mhubConn = new HubConnection(ConnectionString);
            mhubConn.TraceLevel = TraceLevels.All;
            mhubConn.TraceWriter = mWriter;
            mIHubProxy = mhubConn.CreateHubProxy("CentralHub");
            mhubConn.Start().Wait();
            LogEvent(DateTime.Now, "Info", "Reconnection successful.");
            mIHubProxy.On<List<User>>("updateFmds", GetUserFmds);
        }
        catch (Exception e)
        {
            LogEvent(DateTime.Now, "Error", "Reconnection attempt failed.", e.StackTrace, e.Message);
            if (showMessage)
            {
                MessageBox.Show(
                    "There is currently no connection to the server, this application will close, if this issue persists check your network connection or contact support.",
                    "Connection Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                showMessage = false;
            }
            connected = false;
        }
    }

信号R - 处理集线器外部的断开连接

1 个答案: