public ManagerReviewsViewModel()
        {
            _binder = new ReviewsWithAnswersBinder();
            RefreshReviewsCollection();

            ClearTextCommand        = new Command(OnClearTextCommandExecute);
            SaveAnswerCommand       = new Command(OnSaveAnswerCommandExecute, OnSaveAnswerCommandCanExecute);
            SelectionChangedCommand = new Command(OnSelectionChangedCommandExecute);
        }
        public ClientReviewsViewModel(IViewModel parentViewModel, User user)
        {
            _rootViewModel   = ViewModelManager.GetFirstOrDefaultInstance <MainWindowViewModel>();
            _parentViewModel = parentViewModel;
            _binder          = new ReviewsWithAnswersBinder();
            _user            = user;

            BackCommand             = new Command(OnBackCommandExecute);
            RefreshCommand          = new Command(OnRefreshCommandExecute);
            MyReviewsCommand        = new Command(OnMyReviewsCommandExecute);
            AllReviewsCommand       = new Command(OnAllReviewsCommandExecute);
            AddReviewCommand        = new Command(OnAddReviewCommandExecute);
            EditReviewCommand       = new Command(OnEditReviewCommandExecute, OnAnyReviewCommandCanExecute);
            DeleteReviewCommand     = new Command(OnDeleteReviewCommandExecute, OnAnyReviewCommandCanExecute);
            SelectionChangedCommand = new Command(OnSelectionChangedCommandExecute);

            // показываем все отзывы
            OnAllReviewsCommandExecute();
        }