private static void OnContentChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
MyLabel lbl = d as MyLabel;
if (lbl.ContentChanged != null)
{
DependencyPropertyChangedEventArgs args = new DependencyPropertyChangedEventArgs(ContentProperty, e.OldValue, e.NewValue);
lbl.ContentChanged(lbl, args);
}
}