Question

我正在使用SignalR从数据库中为每个连接的客户端获取实时更新。每个clinet都有唯一的数据，因此我只能运行一个实时更新实例。我为每个客户创建一个新对象。问题是该对象具有System.Threading.Timer，它每秒运行一次回调以从数据库获取更新。即使在客户端断开连接后，计时器仍继续运行。我无法在断开连接事件中访问对象。我该如何阻止它？

public class DataHub : Hub
{
private readonly RealTimeData data;


public DataHub(RealTimeData rdata)
{
    data = rdata; 
}

public void Start(Int64 routerId)
{
    data.StartTimer(routerId);
}
}

 public class RealTimeData
{   
private IHubConnectionContext Clients;

public Timer timer;
private readonly int updateInterval = 1000;
private readonly object updateRecievedDataLock = new object();
private bool updateReceivedData = false;
List<Items> allItems = new List<Items>();

 public void StartTimer(Int64 routerId)
{
    this.routerId = routerId;
    timer = new Timer(GetDataForAllItems, null, updateInterval, updateInterval);       
}
  public void GetDataForAllItems(object state)
{
    if (updateReceivedData)
    {
        return;
    }
    lock (updateRecievedDataLock)
    {
        if (!updateReceivedData)
        {
            updateReceivedData = true;
            //get data from database
            allItems = Mapper.Instance.GetDataForAllItems(routerId);
            updateReceivedData = false;
            //send it to the browser for update
            BroadcastData(allItems);
        }
    }
}
}

  public override Task OnDisconnected()
  {
     //before ondisconnect is called datahub construtor is called and a new instace of real time data is made. So I can't have access to previous object here. Where do I stop the timer?
  }

Answer 1

SignalR Hubs是短暂的。 SignalR每次调用包含Hub事件的Hub方法（例如OnDisconnected）时都会实例化一个新的Hub。由于您已将Hub添加到SignalR的依赖项解析程序，这意味着SignalR将为每次连接/断开/调用重新解析集线器。

您最好的选择可能是将您的计时器存放在ConcurrentDictionary<string, Timer>的静态Context.ConnectionId关键字中。

在onDisconnect（）事件中停止计时器

1 个答案: