How to determine if an event is already subscribed

Question

In my .NET application I am subscribing to events from another class. The subscription is conditional. I am subscribing to events when the control is visible and de-subscrib

Answer 1

  /// 

  /// Determine if a control has the event visible subscribed to
  /// 
  /// The control to look for the VisibleChanged event
  /// True if the control is subscribed to a VisibleChanged event, False otherwise
  private bool IsSubscribed(Control controlObject)
  {
     FieldInfo event_visible_field_info = typeof(Control).GetField("EventVisible",
        BindingFlags.Static | BindingFlags.NonPublic);
     object object_value = event_visible_field_info.GetValue(controlObject);
     PropertyInfo events_property_info = controlObject.GetType().GetProperty("Events",
        BindingFlags.NonPublic | BindingFlags.Instance);
     EventHandlerList event_list = (EventHandlerList)events_property_info.GetValue(controlObject, null);
     return (event_list[object_value] != null);
  }