private void AddAllergenButton_OnClick(object sender, RoutedEventArgs e)
        {
            Button button = sender as Button;
            var    dialog = new AddModifyAllergenDialog();

            dialog.Owner = this;
            dialog.ShowDialog();
            if (dialog.DialogResult == true)
            {
                var allergen = dialog.Allergen;
                _viewModel.allergenRepository.AddNewAllergen(allergen);
                _viewModel.Allergens.Add(allergen);
            }
        }
        private void EditAllergenButton_OnClick(object sender, RoutedEventArgs e)
        {
            Button   button = sender as Button;
            Allergen copy   = new Allergen(button.DataContext as Allergen);
            var      dialog = new AddModifyAllergenDialog(copy);

            dialog.Owner = this;
            dialog.ShowDialog();
            if (dialog.DialogResult == true)
            {
                for (int i = 0; i < _viewModel.Allergens.Count; i++)
                {
                    if (_viewModel.Allergens[i].AllergenId == copy.AllergenId)
                    {
                        _viewModel.allergenRepository.ChangeAllergen(_viewModel.Allergens[i], copy);
                        _viewModel.Allergens[i] = copy;
                    }
                }
            }
        }