private static void OnIconChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
Button element = d as Button;
FrameworkElement oldElement = e.OldValue as FrameworkElement;
if (oldElement != null)
{
element.RemoveLogicalChild(oldElement);
}
FrameworkElement newElement = e.NewValue as FrameworkElement;
if (newElement != null)
{
element.AddLogicalChild(newElement);
}
}