protected override void OnPropertyChanged(DependencyPropertyChangedEventArgs e)
{
base.OnPropertyChanged(e);
if (ContentProperty.Equals(e.Property))
{
if (!absoluteLayout.Equals(e.NewValue) && e.NewValue is UIElement)
{
Content = null;
contentView.Children.Clear();
contentView.Children.Add(e.NewValue as UIElement);
Content = absoluteLayout;
}
}
}