protected override void OnBindingContextChanged()
        {
            base.OnBindingContextChanged();

            if (this.BindingContext is Voucher.Models.Voucher)
            {
                _voucher = this.BindingContext as Voucher.Models.Voucher;

                _eventAggregator
                .GetEvent <QrCodeRefreshEvent>()
                .Publish(new VoucherEventArgs(_voucher));

                BeginAnimation();
            }
        }
 public VoucherEventArgs(Voucher.Models.Voucher voucher)
 {
     this.Voucher = voucher;
 }