以下是我的top-menu 在第页上呈现时。。。

<ul id="top-menu" class="menu">
...
<li id="menu-item-28" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-28"><a href="http://localhost:8082/demo/">Demo</a></li>

<li id="menu-item-39" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-39"><a href="http://google.com">Contact Us</a></li>
</ul>

add_filter(\'nav_menu_css_class\' , \'my_nav_special_class\' , 10 , 2);
function my_nav_special_class($classes, $item){
    if($item){ //what should this condition be?
        $classes[] = \'my_custom_class\';
    }
    return $classes;
}