private void PhotosPage_Loaded(object sender, RoutedEventArgs args)
{
//var scrollViewer = ItemsGridView.GetScrollViewer();
//if (scrollViewer == null) return;
//scrollViewer.LayoutUpdated += (s, _) =>
//{
// Debug.WriteLine(scrollViewer.VerticalOffset);
// //scrollViewer.ScrollableHeight == scrollViewer.VerticalOffset //到底
//};
//return;
var scrollViewer = ItemsGridView.FindDescendant <ScrollViewer>();
var scrollbars = scrollViewer.GetDescendantsOfType <ScrollBar>().ToList();
var verticalBar = scrollbars.FirstOrDefault(x => x.Orientation == Orientation.Vertical);
scrollViewer.ViewChanged += (_, e) =>
{
if (e.IsIntermediate)
{
return;
}
TopAppBarButton.Visibility =
scrollViewer.VerticalOffset == 0 ?
Visibility.Collapsed :
Visibility.Visible;
};
TopAppBarButton.Click += (s, e) =>
{
scrollViewer.ChangeView(null, 0, null, false);
};
RefreshAppBarButton.Click += AppBarButton_Click;
}