private void LoadCategory() { DataAccess da = new DataAccess(); List <Dish> dishes = da.GetDishesInCategory(SelectedCategoryId, SelectedMenu.Id); DishesInCategory.Clear(); DishesInCategory.AddRange(dishes); if (DishesInCategory.Count == 0) { SelectedDishInCategory = null; } else { SelectedDishInCategory = DishesInCategory[0]; } NotifyOfPropertyChange(() => DishesInCategory); }