意识到我之前提出的一个问题并不是最清楚的提问方式，所以我试图简化它并添加更多细节，因为我认为我知道我需要做什么只是不知道该怎么做。
我有一个多级菜单 - HTML
<nav id="site-navigation" class="main-navigation" role="navigation">
<button class="menu-toggle" aria-controls="primary-menu" aria-expanded="false">Menu</button>
<div class="partial-refreshable-nav-menu partial-refreshable-nav-menu-1 menu-all-pages-container">
<ul id="primary-menu" class="nav-menu" aria-expanded="false">
<li id="1636" class="menu-item">
<a href="http://wpthemetestdata.wordpress.com/">Home</a></li>
<li id="1637" class="menu-item">
<a href="http://localhost/frytest/blog/">Blog</a></li>
<li id="1638" class="menu-item">
<a href="http://localhost/frytest/front-page/">Front Page</a></li>
<li id="1639" class="menu-item" aria-haspopup="true">
<a href="http://localhost/frytest/about/">About The Tests</a>
<button class="dropdown-toggle" aria-expanded="true">
<span class="screen-reader-text">expand child menu</span>
</button>
<ul class="sub-menu">
<li id="1697" class="menu-item">
<a href="http://localhost/frytest/about/page-image-alignment/">Page Image Alignment</a></li>
<li id="1698" class="menu-item">
<a href="http://localhost/frytest/about/page-markup-and-formatting/">Page Markup And Formatting</a></li>
<li id="1640" class="menu-item">
<a href="http://localhost/frytest/about/clearing-floats/">Clearing Floats</a></li>
<li id="1641" class="menu-item">
<a href="http://localhost/frytest/about/page-with-comments/">Page with comments</a></li>
<li id="1642" class="menu-item">
<a href="http://localhost/frytest/about/page-with-comments-disabled/">Page with comments disabled</a></li>
</ul>
</li>
<li id="1643" class="menu-item" aria-haspopup="true">
<a href="http://localhost/frytest/level-1/">Level 1</a>
<button class="dropdown-toggle" aria-expanded="true">
<span class="screen-reader-text">expand child menu</span>
</button>
<ul class="sub-menu">
<li id="1644" class="menu-item" aria-haspopup="true">
<a href="http://localhost/frytest/level-1/level-2/">Level 2</a>
<button class="dropdown-toggle" aria-expanded="true">
<span class="screen-reader-text">expand child menu</span>
</button>
<ul class="sub-menu">
<li id="1645" class="menu-item">
<a href="http://localhost/frytest/level-1/level-2/level-3/">Level 3</a></li>
<li id="1699" class="menu-item">
<a href="http://localhost/frytest/level-1/level-2/level-3a/">Level 3a</a></li>
<li id="1700" class="menu-item">
<a href="http://localhost/frytest/level-1/level-2/level-3b/">Level 3b</a></li>
</ul>
</li>
<li id="1701" class="menu-item">
<a href="http://localhost/frytest/level-1/level-2a/">Level 2a</a></li>
<li id="1702" class="menu-item">
<a href="http://localhost/frytest/level-1/level-2b/">Level 2b</a></li>
</ul>
</li>
<li id="1646" class="menu-item">
<a href="http://localhost/frytest/lorem-ipsum/">Lorem Ipsum</a></li>
<li id="1703" class="menu-item">
<a href="http://localhost/frytest/page-a/">Page A</a></li>
<li id="1704" class="menu-item">
<a href="http://localhost/frytest/page-b/">Page B</a></li>
</ul>
</div>
</nav>
每个附加了子菜单的元素都有一个按钮，用作打开和关闭附加元素的开关。我一直在尝试对菜单的功能进行编程，但遇到了一个症结所在。单击下拉切换时，将运行此 javascript：
container.find( '.dropdown-toggle' ).click(
function( e ){
var _this = $( this );
e.preventDefault();
$('.dropdown-toggle.toggle-on').toggleClass('toggle-on');
$('.sub-menu.toggled-on').toggleClass('toggled-on');
_this.parents('.sub-menu').toggleClass('toggled-on');
//This is the line that doesnt run
_this.parents('.dropdown-toggle').toggleClass('toggle-on');
//toggles the chevron clicked to go on
_this.toggleClass( 'toggle-on' );
_this.next( '.children, .sub-menu' ).toggleClass( 'toggled-on' );
//Below has no effect of expansion
_this.attr( 'aria-expanded', _this.attr( 'aria-expanded' ) === 'false' ? 'true' : 'false' );
_this.html( _this.html() === screenReaderText.expand ? screenReaderText.collapse : screenReaderText.expand );
}
);
不工作的线路是
_this.parents(".dropdown-toggle").toggleClass("toggle-on")
它上面的行确实有效，但这一行无效。我认为这是因为虽然按钮在层次上位于单击的按钮之上，但它不计为父级，因为它与<ul>在上面一行中选择的标签处于同一级别。
我将如何为单击的直接上方的所有按钮切换类？