private void btnThemBan_Click(object sender, EventArgs e)
        {
            int soNguoi = 0;

            try
            {
                soNguoi = int.Parse(maskedTextBox_SoNguoi.Text);
            }
            catch
            {
            }
            frm_FormPhu_NhapSo f = new frm_FormPhu_NhapSo();

            f.ShowDialog();
            int SoBan = f.Number;

            if (SoBan <= 0)
            {
                return;
            }
            if (TimBanCoTrongHeThong(SoBan) == null)
            {
                Tables tempTable = new Tables(1, SoBan, this.txt_ViTriBan.Text, soNguoi);
                IDBanDangChon = Tables.AddWithOutput(tempTable);
                Orders tempOrder = new Orders(IDBanDangChon, this.txt_NhanVienOrder.Text, DateTime.Now, 0, 0, 0, 0);
                objOrder.Add(tempOrder);
                LoadDSBan();
                IDOrderDangChon = Orders.GetOrderByTableID(IDBanDangChon)[0].OrderID;
            }
            else
            {
                MessageBox.Show("Bàn này đã tồn tại trong hệ thống", "Lỗi", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            this.lblSoBan.Text = SoBan.ToString();
        }
        private void sửaToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (this.listView_CacMonDaGoi.Items.Count != 0 && this.listView_CacMonDaGoi.SelectedItems.Count != 0)
            {
                frm_FormPhu_NhapSo f = new frm_FormPhu_NhapSo();
                f.ShowDialog();
                int   ID      = int.Parse(this.listView_CacMonDaGoi.SelectedItems[0].SubItems[6].Text);
                int   SoLuong = f.Number;
                float GiaCa   = Converts.ReturnFloat(this.listView_CacMonDaGoi.SelectedItems[0].SubItems[3].Text);
                try
                {
                    OrderDetails.Update(ID, SoLuong, GiaCa);
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }

                LoadListView_CacMonDaChon();
            }
        }
        private void btn_ThemMon_Click(object sender, EventArgs e)
        {
            frm_FormPhu_NhapSo f = new frm_FormPhu_NhapSo();

            f.ShowDialog();

            if (f.Number <= 0)
            {
                MessageBox.Show("Dữ liệu vừa nhập không hợp lệ", "Lỗi", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }
            if (this.listView_Products.Items.Count != 0 && this.listView_Products.SelectedItems.Count != 0)
            {
                int   productID = int.Parse(this.listView_Products.SelectedItems[0].SubItems[3].Text);
                float Price     = Prices.GetPriceByDateAndProductID(DateTime.Now, productID);
                IDOrderDangChon = Orders.GetOrderByTableID(IDBanDangChon)[0].OrderID;
                OrderDetails tempOrderDeTail = new OrderDetails(IDOrderDangChon, productID, Price, f.Number, 0);
                objOrderDetail.Add(tempOrderDeTail);
                LoadListView_CacMonDaChon();
                LoadDSBan();
            }
        }