elmah.ir-post120-code8.cs

public Guid PlaceOrder(Guid customerId, ShoppingCart shoppingCart)
{
  foreach (var item in shoppingCart.Items)
  {
    if (item.Quantity == 0)
    {
      throw new InvalidOrderException();
    }
  }
  var customer = _customerService.GetCustomer(customerId);
  var order = new Order();
  return _orderDataService.Save(order);
}