Probably the most used solution is to keep a static variable containing users currently connected and overriding OnConnect
and OnDisconnect
or implementing IDisconnect
depending on the version that you use.
You would implement something like this:
public class MyHub : Hub
{
private static List<string> users = new List<string>();
public override Task OnConnected()
{
users.Add(Context.ConnectionId);
return base.OnConnected();
}
//SignalR Verions 1 Signature
public override Task OnDisconnected()
{
users.Remove(Context.ConnectionId);
return base.OnDisconnected();
}
//SignalR Version 2 Signature
public override Task OnDisconnected(bool stopCalled)
{
users.Remove(Context.ConnectionId);
return base.OnDisconnected(stopCalled);
}
// In your delegate check the count of users in your list.
}