private void btnAddFood_Click(object sender, EventArgs e) { Table table = lsvBill.Tag as Table; if (table == null) { MessageBox.Show("Vui lòng chọn bàn"); return; } int idBill = billBUS.GetUncheckBillIDByTableID(table.IdTable); int foodID = (int)dataGridViewListFood.CurrentRow.Cells["idFood"].Value; int count = (int)nmFoodCount.Value; if (idBill == -1) { billBUS.InsertBill(table.IdTable); BillInforBUS.InsertBillInfo(billBUS.GetMaxIDBill(), foodID, count); } else { BillInforBUS.InsertBillInfo(idBill, foodID, count); } ShowBill(table.IdTable); LoadTable(); }