SignalR - Checking if a user is still connected

Question

I have a hub with method that is called client-side. This method launches a timer with a delegate that runs every 10 seconds. Since it wouldn\'t make sense to keep running t

Answer 1

I have done this way:

public class PrincipalCommunicator
    {
        public readonly static Lazy _instance = new Lazy(
                () => new PrincipalCommunicator(GlobalHost.ConnectionManager.GetHubContext())
            );

        public List ConnectedUsers { get; set; }

        private IHubContext _context;

        private PrincipalCommunicator(IHubContext context)
        {
            ConnectedUsers = new List();
            _context = context;
        }

        public static PrincipalCommunicatorInstance
        {
            get
            {
                return _instance.Value;
            }
        }

        public bool IsUserConnected(string user)
        {
            return UsuariosConectados.Contains(user);
        }
    }

    public class PrincipalHub : Hub
    {
        public override Task OnConnected()
        {
            PrincipalComunicador.Instance.UsuariosConectados.Add(Context.User.Identity.Name);

            return base.OnConnected();
        }

        public override Task OnDisconnected(bool stopCalled)
        {
            PrincipalComunicador.Instance.UsuariosConectados.Remove(Context.User.Identity.Name);
            return base.OnDisconnected(stopCalled);
        }
    }
}

This way, all logic to send something to client stays in one place, like the example and you can know if a user is connected anywhere in the code.