我使用一个函数在我的页面中创建面包屑，它可以工作：

function the_breadcrumb() {
    $currentBefore = \'<li><a>\';
    $currentAfter = \'</a></li>\';
    if ( !is_home() && !is_front_page() || is_paged() ) {
        echo \'<nav class="breadcrumb"><ul>\';
        global $post;
        if ( is_page() && !$post->post_parent ) {
            echo $currentBefore;
            the_title();
            echo $currentAfter; }
        elseif ( is_page() && $post->post_parent ) {
            $parent_id  = $post->post_parent;
            $breadcrumbs = array();
            while ($parent_id) {
                $page = get_page($parent_id);
                $breadcrumbs[] = \'<li><a href="\' . get_permalink($page->ID) . \'">\' . get_the_title($page->ID) . \'</a></li>\';
                $parent_id  = $page->post_parent;
            }
            $breadcrumbs = array_reverse($breadcrumbs);
            foreach ($breadcrumbs as $crumb) echo $crumb;
            echo $currentBefore;
            the_title();
            echo $currentAfter;
        }
        echo \'</ul></nav>\';
    }
}

但我希望此函数将post\\u id（页面的id）作为参数，以便在为该页面创建面包屑的AJAX函数中使用它：

function the_ajax_breadcrumb($post_id) {
    ob_start();
    $args = array(\'page_id\' => $post_id);
    $the_query = new WP_Query($args);
    $currentBefore = \'<li><a>\';
    $currentAfter = \'</a></li>\';
    while ( $the_query->have_posts() ) {
        $the_query->the_post();
        if ( !is_home() && !is_front_page() || is_paged() ) {
            echo \'<nav class="breadcrumb"><ul>\';
            if ( is_page() && !$the_query->post->post_parent ) {
                echo $currentBefore;
                the_title();
                echo $currentAfter;
            }
            elseif ( is_page() && $the_query->post->post_parent ) {
                $parent_id  = $the_query->post->post_parent;
                $breadcrumbs = array();
                while ($parent_id) {
                    $page = get_page($parent_id);
                    $breadcrumbs[] = \'<li><a href="\' . get_permalink($page->ID) . \'">\' . get_the_title($page->ID) . \'</a></li>\';
                    $parent_id  = $page->post_parent;
                }
                $breadcrumbs = array_reverse($breadcrumbs);
                foreach ($breadcrumbs as $crumb) echo $crumb;
                echo $currentBefore;
                the_title();
                echo $currentAfter;
            }
            else {
                echo \'<li>nope</li>\';
            }
            echo \'</ul></nav>\';
        }
    }
    $result = ob_get_clean();
    return $result;
}

但它输出“nope”（else条件）。。。我在这里错过了什么让这一切成功？非常感谢您的时间和帮助。

function the_ajax_breadcrumb($post_id) {
    ob_start();
    $args = array(\'page_id\' => $post_id);
    $the_query = new WP_Query($args);
    $currentBefore = \'<li><a>\';
    $currentAfter = \'</a></li>\';
    while ( $the_query->have_posts() ) {
        $the_query->the_post();
        if ( !is_home() && !is_front_page() || is_paged() ) {
            echo \'<nav class="breadcrumb"><ul>\';
            if ( !$the_query->post->post_parent ) {
                echo $currentBefore;
                the_title();
                echo $currentAfter;
            }
            elseif ( $the_query->post->post_parent ) {
                $parent_id  = $the_query->post->post_parent;
                $breadcrumbs = array();
                while ($parent_id) {
                    $page = get_page($parent_id);
                    $breadcrumbs[] = \'<li><a href="\' . get_permalink($page->ID) . \'">\' . get_the_title($page->ID) . \'</a></li>\';
                    $parent_id  = $page->post_parent;
                }
                $breadcrumbs = array_reverse($breadcrumbs);
                foreach ($breadcrumbs as $crumb) echo $crumb;
                echo $currentBefore;
                the_title();
                echo $currentAfter;
            }
            else {
                echo \'<li>nope</li>\';
            }
            echo \'</ul></nav>\';
        }
    }
    $result = ob_get_clean();
    return $result;
}