public void showBill(int id)
        {
            lvBill.Items.Clear();
            List <BillInfo> listBillInfo = new List <BillInfo>();
            //label1.Text = billID.ToString();

            string    query        = "select f.id, f.name, bi.count, f.price, (f.price*bi.count*(100-f.discount))/100 as totalPrice, f.discount from Bill as b, BillInfo as bi, Food as f where bi.idBill = b.id and bi.idFood = f.id and b.status = 0 and b.idTable = " + id;
            DataTable dataBillInfo = DataProvider.Instance.ExecuteQuery(query);

            foreach (DataRow row in dataBillInfo.Rows)
            {
                BillInfo info = new BillInfo(row);
                listBillInfo.Add(info);
            }


            float totalPrice = 0;

            foreach (BillInfo item in listBillInfo)
            {
                ListViewItem lvItem = new ListViewItem(item.NameFood.ToString());
                lvItem.SubItems.Add(item.Count.ToString());
                lvItem.SubItems.Add(item.Price.ToString());
                lvItem.SubItems.Add(item.Discount.ToString());
                lvItem.SubItems.Add(item.TotalPrice.ToString());



                lvItem.SubItems.Add(item.IdFood.ToString());



                totalPrice += item.TotalPrice;

                lvBill.Items.Add(lvItem);
            }

            CultureInfo culture = new CultureInfo("vi-VN");

            txtTotalPrice.Text = totalPrice.ToString("c", culture);

            TongTienThanhToan = totalPrice;



            //DataTable dataBillInfo = DataProvider.Instance.ExecuteQuery("select * from BillInfo where idBill = " + billID);

            //foreach (DataRow row in dataBillInfo.Rows)
            //{
            //    BillInfo info = new BillInfo(row);
            //    listBillInfo.Add(info);
            //}


            //foreach (BillInfo item in listBillInfo)
            //{
            //    ListViewItem lvItem = new ListViewItem(item.IdFood.ToString());
            //    lvItem.SubItems.Add(item.Count.ToString());

            //    lvBill.Items.Add(lvItem);
            //}
        }
        private void printDocument1_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
        {
            e.Graphics.DrawString("HÓA ĐƠN BÁN HÀNG", new Font("Segoe UI", 21, FontStyle.Bold), Brushes.Black, new Point(270, 100));
            e.Graphics.DrawString("Ngày bán: " + DateTime.Now.ToString(), new Font("Arial", 15, FontStyle.Regular), Brushes.Black, new Point(50, 200));
            e.Graphics.DrawString("HĐ: " + idBill, new Font("Arial", 15, FontStyle.Regular), Brushes.Black, new Point(700, 200));
            e.Graphics.DrawString("______________________________________________________________", new Font("Arial", 15, FontStyle.Regular), Brushes.Black, new Point(50, 270));



            e.Graphics.DrawString("Mặt hàng", new Font("Arial", 15, FontStyle.Bold), Brushes.Black, new Point(50, 320));
            e.Graphics.DrawString("SL", new Font("Arial", 15, FontStyle.Bold), Brushes.Black, new Point(250, 320));
            e.Graphics.DrawString("Đơn giá", new Font("Arial", 15, FontStyle.Bold), Brushes.Black, new Point(350, 320));
            e.Graphics.DrawString("KM (%)", new Font("Arial", 15, FontStyle.Bold), Brushes.Black, new Point(530, 320));
            e.Graphics.DrawString("Thành tiền", new Font("Arial", 15, FontStyle.Bold), Brushes.Black, new Point(680, 320));



            List <BillInfo> listBillInfo = new List <BillInfo>();
            //label1.Text = billID.ToString();

            string    query        = "select f.id, f.name, bi.count, f.price, (f.price*bi.count*(100-f.discount))/100 as totalPrice, f.discount from Bill as b, BillInfo as bi, Food as f where bi.idBill = b.id and bi.idFood = f.id and b.status = 0 and b.idTable = " + QuanLyBanHang.IDTable;
            DataTable dataBillInfo = DataProvider.Instance.ExecuteQuery(query);

            foreach (DataRow row in dataBillInfo.Rows)
            {
                BillInfo info = new BillInfo(row);
                listBillInfo.Add(info);
            }



            int point = 320;

            foreach (BillInfo item in listBillInfo)
            {
                point += 50;
                e.Graphics.DrawString(item.NameFood.ToString(), new Font("Arial", 15, FontStyle.Regular), Brushes.Black, new Point(50, point));
                e.Graphics.DrawString(item.Count.ToString(), new Font("Arial", 15, FontStyle.Regular), Brushes.Black, new Point(250, point));
                e.Graphics.DrawString(item.Price.ToString(), new Font("Arial", 15, FontStyle.Regular), Brushes.Black, new Point(350, point));
                e.Graphics.DrawString(item.Discount.ToString(), new Font("Arial", 15, FontStyle.Regular), Brushes.Black, new Point(530, point));
                e.Graphics.DrawString(item.TotalPrice.ToString(), new Font("Arial", 15, FontStyle.Regular), Brushes.Black, new Point(680, point));
            }



            point += 50;
            e.Graphics.DrawString("______________________________________________________________", new Font("Arial", 15, FontStyle.Regular), Brushes.Black, new Point(50, point));
            point += 50;
            e.Graphics.DrawString("TỔNG TIỀN PHẢI THANH TOÁN", new Font("Arial", 15, FontStyle.Bold), Brushes.Black, new Point(50, point));
            e.Graphics.DrawString(txtTienPhaiThanhToan.Text.ToString(), new Font("Arial", 15, FontStyle.Regular), Brushes.Black, new Point(680, point));
            point += 50;

            e.Graphics.DrawString("TIỀN KHÁCH TRẢ", new Font("Arial", 15, FontStyle.Bold), Brushes.Black, new Point(50, point));
            e.Graphics.DrawString(txtTienKhachTra.Text.ToString(), new Font("Arial", 15, FontStyle.Regular), Brushes.Black, new Point(680, point));
            point += 50;

            e.Graphics.DrawString("TIỀN TRẢ LẠI", new Font("Arial", 15, FontStyle.Bold), Brushes.Black, new Point(50, point));
            e.Graphics.DrawString((float.Parse(txtTienKhachTra.Text) - float.Parse(txtTienPhaiThanhToan.Text)).ToString(), new Font("Arial", 15, FontStyle.Regular), Brushes.Black, new Point(680, point));
            point += 100;

            e.Graphics.DrawString("CẢM ƠN QUÝ KHÁCH VÀ HẸN GẶP LẠI", new Font("Segoe UI", 18, FontStyle.Bold), Brushes.Black, new Point(195, point));
        }