private static void OnCommandChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
RibbonTextBox textBox = (RibbonTextBox)d;
ICommand oldCommand = (ICommand)e.OldValue;
ICommand newCommand = (ICommand)e.NewValue;
if (oldCommand != null)
{
textBox.UnhookCommand(oldCommand);
}
if (newCommand != null)
{
textBox.HookCommand(newCommand);
}
RibbonHelper.OnCommandChanged(d, e);
}
