partial void OnApplyTemplatePartial()
{
// NativePanel may not exist if we're using a non-virtualizing ItemsPanel.
if (NativePanel != null)
{
// Propagate the DataContext manually, since ItemsPanelRoot isn't really part of the visual tree
ItemsPanelRoot.SetValue(DataContextProperty, DataContext, DependencyPropertyValuePrecedences.Inheritance);
if (ScrollViewer?.Style == null)
{
throw new InvalidOperationException($"Performance hit: {this} is using a ScrollViewer in its template with a default style, which would break virtualization. A Style containing {nameof(ListViewBaseScrollContentPresenter)} must be used.");
}
if (ScrollViewer != null)
{
NativePanel.HorizontalScrollBarVisibility = ScrollViewer.HorizontalScrollBarVisibility;
NativePanel.VerticalScrollBarVisibility = ScrollViewer.VerticalScrollBarVisibility;
}
}
else
{
if (ScrollViewer?.Style != null && ScrollViewer.Style == ResourceResolver.GetSystemResource <Style>("ListViewBaseScrollViewerStyle")) //TODO: this, too, properly
{
// We're not using NativeListViewBase so we need a 'real' ScrollViewer, remove the internal custom style
ScrollViewer.Style = null;
}
}
}
