private void ListViewItem_OnHolding(object sender, HoldingRoutedEventArgs e)
        {
            var        senderElement = sender as FrameworkElement;
            FlyoutBase flyoutBase    = FlyoutBase.GetAttachedFlyout(senderElement);

            if (flyoutBase != null)
            {
                flyoutBase.ShowAtEx(senderElement);
            }
        }