public void AddActiveArea(Rectangle area, Bitmap infoImage) { OverlayImage info = new OverlayImage(infoImage, .2f, .2f, mWhereWindow); CameraPositionTrigger trigger = new CameraPositionTrigger(Manager.Coordinator); mActiveAreas.Add(trigger); trigger.Triggered += () => { mInfoImages.Add(info); mWhereButton.Active = true; }; trigger.Left += () => { mInfoImages.Remove(info); mWhereButton.Active = mInfoImages.Count > 0; }; }