private static void BeginSetFocus([NotNull] this ItemsControl selector, [CanBeNull] object selectedItem)
{
selector.BeginInvoke(() =>
{
var container = selector.ItemContainerGenerator.ContainerFromItem(selectedItem) as FrameworkElement;
if (container == null)
{
return;
}
var child = container.VisualDescendantsAndSelf().OfType <UIElement>().FirstOrDefault(item => item.Focusable);
child?.Focus();
});
}
