private void listView_Click(object sender, EventArgs e)
        {
            flag      = true;
            flagimage = true;
            ComboBLL comboBLL = new ComboBLL();

            txtComboName.Text = listViewCombo.SelectedItems[0].SubItems[1].Text;
            dayStart.Value    = DateTime.Parse(listViewCombo.SelectedItems[0].SubItems[2].Text);
            dayEnd.Value      = DateTime.Parse(listViewCombo.SelectedItems[0].SubItems[3].Text);
            numDiscount.Text  = listViewCombo.SelectedItems[0].SubItems[5].Text;
            txtTotal.Text     = listViewCombo.SelectedItems[0].SubItems[4].Text;
            total             = int.Parse(txtTotal.Text.Replace(",", ""));
            int idcombo = int.Parse(listViewCombo.SelectedItems[0].ImageKey);

            LoadPreviewImage(idcombo);
            id = idcombo;
            btnThem.Enabled = true;
            btnXoa.Enabled  = true;
            btnSua.Enabled  = true;
            list            = comboBLL.ListIDProduct(id);
        }
        private void btnAdd_Click(object sender, EventArgs e)
        {
            LapDonHangBLL donHangBLL = new LapDonHangBLL();

            if (newCus)
            {
                donHangBLL.AddKhach(firstname, lastname, phone, address);
            }
            int totalqty = 0;

            foreach (ObjCombo item in arr_combo)
            {
                totalqty += item.Quantity;
                ComboBLL  comboBLL = new ComboBLL();
                ArrayList listid   = comboBLL.ListIDProduct(item.Combo.Id);
                foreach (int a in listid)
                {
                    ProductBLL productBLL = new ProductBLL();
                    productBLL.EditProduct(item.Quantity, a);
                }
            }
            foreach (ObjProduct item in arr_product)
            {
                totalqty += item.Quantity;
                ProductBLL productBLL = new ProductBLL();
                productBLL.EditProduct(item.Quantity, item.Product.id);
            }
            Invoice invoice = new Invoice();

            if (newCus)
            {
                invoice.customer_id = donHangBLL.getIdCustommer();
            }
            else
            {
                invoice.customer_id = idcus;
            }
            invoice.customeraddress = address;
            invoice.totalmoney      = txtThanhtien.Text.Replace(",", "");
            invoice.amount          = totalqty.ToString();
            invoice.creatday        = DateTime.Now;
            invoice.ordernote       = "123";
            invoice.postcode        = "123";
            invoice.status          = "Done";
            donHangBLL.AddInvoice(invoice);
            string products = "";

            if (arr_product.Count != 0)
            {
                products = JsonConvert.SerializeObject(arr_product);
            }
            string combos = "";

            if (arr_combo.Count != 0)
            {
                combos = JsonConvert.SerializeObject(arr_combo);
            }
            donHangBLL.AddInvoiceDetail(products, combos);
            LoadListViewSelect();
            arr_combo   = new ArrayList();
            arr_product = new ArrayList();
            MessageBox.Show("Đã thêm đơn hàng thành công");
        }