private void PrintBill_Click(object sender, RoutedEventArgs e) { if (Project.Instance.Bill.FullPrice == 0) { MessageBox.Show("Bill cannot be empty", "Congratulations", MessageBoxButton.OK, MessageBoxImage.Information); this.Close(); } if (IsValid() == false) { return; } Project.Instance.Bill.DateOfSale = DateTime.Now; Project.Instance.Bill.BillNo = DateTime.Now.Millisecond; BillDAO.Create(Project.Instance.Bill); foreach (var b in Project.Instance.Bill.FurnitureForSaleList) { foreach (var f in Project.Instance.FurnitureList) { if (f.ID == b.ID) { BillDAO.AddFurnitureOnBill(Project.Instance.Bill, f); f.Quantity -= b.Quantity; FurnitureDAO.Update(f); } } } foreach (var b in Project.Instance.Bill.AdditionalServiceList) { foreach (var a in Project.Instance.AdditionalServicesList) { BillDAO.AddAdditionalServiceOnBill(Project.Instance.Bill, a); } } MessageBox.Show("Success!", "Congratulations", MessageBoxButton.OK, MessageBoxImage.Information); Project.Instance.Bill = new Bill(); MainWindow.DeleteSoldFurniture(); this.Close(); }