public void Attach(DependencyObject associatedObject)
{
this.AssociatedObject = associatedObject;
ListViewBase dataView = this.AssociatedObject as ListViewBase;
if (dataView != null)
{
ScrollViewer scrollViewer = dataView.GetDescendantsOfType <ScrollViewer>().FirstOrDefault();
if (scrollViewer != null)
{
this.AttachScrollBar(scrollViewer);
}
else
{
RoutedEventHandler loadedHandler = null;
loadedHandler = (sender, e) =>
{
scrollViewer = dataView.GetDescendantsOfType <ScrollViewer>().FirstOrDefault();
this.AttachScrollBar(scrollViewer);
dataView.Loaded -= loadedHandler;
};
dataView.Loaded += loadedHandler;
}
}
}
public static void ScrollIntoViewSmoothly(this ListViewBase listViewBase, object item, ScrollIntoViewAlignment alignment)
{
if (listViewBase == null)
{
throw new ArgumentNullException(nameof(listViewBase));
}
ScrollViewer scrollViewer = listViewBase.GetDescendantsOfType <ScrollViewer>().First();
double originHorizontalOffset = scrollViewer.HorizontalOffset;
double originVerticalOffset = scrollViewer.VerticalOffset;
EventHandler <object> layoutUpdatedHandler = null;
layoutUpdatedHandler = delegate
{
listViewBase.LayoutUpdated -= layoutUpdatedHandler;
double targetHorizontalOffset = scrollViewer.HorizontalOffset;
double targetVerticalOffset = scrollViewer.VerticalOffset;
EventHandler <ScrollViewerViewChangedEventArgs> scrollHandler = null;
scrollHandler = (sender, e) =>
{
scrollViewer.ViewChanged -= scrollHandler;
scrollViewer.ChangeView(targetHorizontalOffset, targetVerticalOffset, null);
};
scrollViewer.ViewChanged += scrollHandler;;
scrollViewer.ChangeView(originHorizontalOffset, originVerticalOffset, null, true);
};
listViewBase.LayoutUpdated += layoutUpdatedHandler;
listViewBase.ScrollIntoView(item, alignment);
}