void ChangeView(int page, int line = -1)
{
if (line >= 0)
{
ContentListView.UpdateLayout();
if (ContentListView.Items.Count == 0)
{
ContentListView.SetValue(ContentListViewChangeViewRequestProperty, line);
ContentListView.SizeChanged += ContentListView_SizeChanged;
}
else if (line < ContentListView.Items.Count)
{
ContentListView.ScrollIntoView(ViewModel.Contents[line], ScrollIntoViewAlignment.Leading);
}
}
}