private static void OnSetRegionNameCallback(DependencyObject element, DependencyPropertyChangedEventArgs args)
{
if (element != null)
{
IRegionManager regionManager = element.GetValue(RegionManagerProperty) as IRegionManager;
if (regionManager != null)
{
string oldRegionName = args.OldValue as string;
if (oldRegionName != null)
{
regionManager.Regions.Remove(oldRegionName);
}
string newRegionName = args.NewValue as string;
if (newRegionName != null)
{
regionManager.AttachNewRegion(element, newRegionName);
}
}
}
}