public override void OnPageLoad(object sender, EventArgs e)
        {
            base.OnPageLoad(sender, e);

            this._voucherProductVM = new GiftCardProductVM();
            this._facade           = new GiftCardFacade(this);
            selected = new List <int>();
            this.voucherProduct.ProductSelected += voucherProduct_ProductSelected;

            _facade.GetGiftCardC3SysNo((no) =>
            {
                _c3SysNo = no;
            });
            if (RequestSysNo.HasValue)
            {
                this._voucherProductVM.SysNo = RequestSysNo.Value;

                _facade.GetGiftVoucherProductInfo(RequestSysNo.Value, (ret) =>
                {
                    this._voucherProductVM = ret;
                    foreach (var item in this._voucherProductVM.RelationProducts)
                    {
                        item.IsChecked = false;
                    }
                    SetDataContext();
                });
            }
            else
            {
                //this.voucherProductgd
                SetDataContext();
            }
        }