我用这个助行器在functions.php

class main_menu_walker extends Walker_Nav_Menu {
    function start_el(&$output, $item, $depth, $args) {
        global $wp_query;
        $indent = ( $depth ) ? str_repeat( "\\t", $depth ) : \'\';

        $class_names = $value = \'\';

        $classes = empty( $item->classes ) ? array() : (array) $item->classes;

        $class_names = join( \' \', apply_filters( \'nav_menu_css_class\', array_filter( $classes ), $item ) );
        $class_names = \' class="\'. esc_attr( $class_names ) . \' nav-item"\';

        $output .= $indent . \'<li id="menu-item-\'. $item->ID . \'"\' . $value . $class_names .\'>\';

        $attributes  = ! empty( $item->attr_title ) ? \' title="\'  . esc_attr( $item->attr_title ) .\'"\' : \'\';
        $attributes .= ! empty( $item->target )     ? \' target="\' . esc_attr( $item->target     ) .\'"\' : \'\';
        $attributes .= ! empty( $item->xfn )        ? \' rel="\'    . esc_attr( $item->xfn        ) .\'"\' : \'\';
        $attributes .= ! empty( $item->url )        ? \' href="\'   . esc_attr( $item->url        ) .\'"\' : \'\';

        $item_output = $args->before;
        if ( $args->walker->has_children && 0 === $depth ) {
            $item_output .= \'<span class="nav-link">\';
        } else {
            $item_output .= \'<a class="nav-link" \' . $attributes . \'>\';
        }

        $item_output .= $args->link_before .apply_filters( \'the_title\', $item->title, $item->ID );
        $item_output .= ( $args->walker->has_children && 0 === $depth ) ? \' </span>\' : \'</a>\';
        $item_output .= $args->after;
        $output .= apply_filters( \'walker_nav_menu_start_el\', $item_output, $item, $depth, $args );
    }
}

获取this structure menu:

<ul class="nav navbar-nav nav__top-menu">
    <li class="nav-item">
        <a class="nav-link" href="#">Home</a>
    </li>
    <li class="nav-item">
        <span class="nav-link">About</span>
        <ul class="sub-menu">
            <li class="nav-item">
                <a class="nav-link" href="#">text 1</a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">text 2</a>
            </li>   
        </ul>
    </li>
</ul>

如果父项具有子菜单-正在成为span

如何制作-单击父项并转到第一个子项？

Update

我找到了这个plugin. 首先发布的搜索子页function has_published_children. 在我的菜单中，页面的位置可能会改变。需要的功能，搜索页面不是按发布日期，而是按位置在菜单中。

<?php
    /*
        Template Name: Redirect To First Child
    */
    if ( have_posts() ) {
        while ( have_posts() ) {
            the_post();
            $pagekids = get_pages( "child_of=" . $post->ID . "&sort_column=menu_order" );
            $firstchild = $pagekids[0];
            wp_redirect( get_permalink( $firstchild->ID ) );
        }
    }
?>