private static void OnIndexChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
SlideSwitchPanel panel = d as SlideSwitchPanel;
if (e.Property == SlideSwitchPanel.IndexProperty)
{
int newValue = (int)e.NewValue;
int oldValue = (int)e.OldValue;
panel.OnIndexChanged(oldValue, newValue);
}
}
