public DesignerControlViewModel(IEventAggregator eventAggregator) { _eventAggregator = eventAggregator; _refreshDesignerEvent = _eventAggregator.GetEvent <RefreshDesignerEvent>(); _refreshDesignerEvent.Subscribe(OnRefreshDesigner, ThreadOption.UIThread, false, tab => tab.Guid == _fileGuid); LoadedCommand = new DelegateCommand <RoutedEventArgs>(OnLoaded); SnapshotCommand = new DelegateCommand(OnSnapshot, CanSnapshot); }