// добавление нового блюда в бд
 public void AddDish(Dish dish)
 {
     using (_context = new Context())
     {
         if (dish.Category != null)
             _context.Categories.Attach(dish.Category);
         _context.Dishes.Add(dish);
         _context.SaveChanges();
     }
 }
 // добавление записи в таблицу истории
 public void AddEatingHistoryItem(Dish dish, float quantity)
 {
     EatingHistoryItem eatingHistoryItem = new EatingHistoryItem
     {
         Date = DateTime.Now.Date,
         Dish = dish,
         Quantity = quantity,
         Calories = dish.Calories / 100 * quantity,
         Fats = dish.Fats / 100 * quantity,
         Proteins = dish.Proteins / 100 * quantity,
         Carbohydrates = dish.Carbohydrates / 100 * quantity
     };
     using (_context = new Context())
     {
         _context.Dishes.Attach(dish);
         _context.EatingHistory.Add(eatingHistoryItem);
         _context.SaveChanges();
     }
 }
 private void Button_Click(object sender, RoutedEventArgs e)
 {
     try
     {
         Dish dish = new Dish
         {
             Category = (Category)this.comboBox.SelectedItem,
             Name = this.textBoxName.Text,
             Calories = float.Parse(this.textBoxCalories.Text),
             Proteins = float.Parse(this.textBoxProteins.Text),
             Fats = float.Parse(this.textBoxFats.Text),
             Carbohydrates = float.Parse(this.textBoxCarbohydrates.Text)
         };
         _viewModel.AddNewItem(dish);
         this.Close();
     }
     catch
     {
         MessageBox.Show("Проверьте правильность введённых данных");
     }
 }
 // добавление нового блюда в бд
 public void AddNewItem(Dish dish)
 {
     _repo.AddDish(dish);
 }