可以将自定义助行器传递给wp_list_pages() 使用$walker 参数

这是一个名为WPSE_Walker_Page_Comment_Count() 它基于默认的页面遍历器，Walker_Page(). 我们只是在覆盖start_el() 方法。已自定义输出以包括注释计数。

首先，将walker代码添加到主题的functions.php 或插件：

class WPSE_Walker_Page_Comment_Count extends Walker_Page {
    // Copied from Walker_Page::start_el() core version v4.7.4.
    /**
     * Outputs the beginning of the current element in the tree.
     *
     * @see Walker::start_el()
     * @since 2.1.0
     * @access public
     *
     * @param string  $output       Used to append additional content. Passed by reference.
     * @param WP_Post $page         Page data object.
     * @param int     $depth        Optional. Depth of page. Used for padding. Default 0.
     * @param array   $args         Optional. Array of arguments. Default empty array.
     * @param int     $current_page Optional. Page ID. Default 0.
     */
    public function start_el( &$output, $page, $depth = 0, $args = array(), $current_page = 0 ) {
        if ( isset( $args[\'item_spacing\'] ) && \'preserve\' === $args[\'item_spacing\'] ) {
            $t = "\\t";
            $n = "\\n";
        } else {
            $t = \'\';
            $n = \'\';
        }
        if ( $depth ) {
            $indent = str_repeat( $t, $depth );
        } else {
            $indent = \'\';
        }

        $css_class = array( \'page_item\', \'page-item-\' . $page->ID );

        if ( isset( $args[\'pages_with_children\'][ $page->ID ] ) ) {
            $css_class[] = \'page_item_has_children\';
        }

        if ( ! empty( $current_page ) ) {
            $_current_page = get_post( $current_page );
            if ( $_current_page && in_array( $page->ID, $_current_page->ancestors ) ) {
                $css_class[] = \'current_page_ancestor\';
            }
            if ( $page->ID == $current_page ) {
                $css_class[] = \'current_page_item\';
            } elseif ( $_current_page && $page->ID == $_current_page->post_parent ) {
                $css_class[] = \'current_page_parent\';
            }
        } elseif ( $page->ID == get_option(\'page_for_posts\') ) {
            $css_class[] = \'current_page_parent\';
        }

        /**
         * Filters the list of CSS classes to include with each page item in the list.
         *
         * @since 2.8.0
         *
         * @see wp_list_pages()
         *
         * @param array   $css_class    An array of CSS classes to be applied
         *                              to each list item.
         * @param WP_Post $page         Page data object.
         * @param int     $depth        Depth of page, used for padding.
         * @param array   $args         An array of arguments.
         * @param int     $current_page ID of the current page.
         */
        $css_classes = implode( \' \', apply_filters( \'page_css_class\', $css_class, $page, $depth, $args, $current_page ) );

        if ( \'\' === $page->post_title ) {
            /* translators: %d: ID of a post */
            $page->post_title = sprintf( __( \'#%d (no title)\' ), $page->ID );
        }

        $args[\'link_before\'] = empty( $args[\'link_before\'] ) ? \'\' : $args[\'link_before\'];
        $args[\'link_after\'] = empty( $args[\'link_after\'] ) ? \'\' : $args[\'link_after\'];

        // Get the comment count for the page.
        $comments_number = get_comments_number( $page->ID );
        if ( 0 == $comments_number ) {
            $comments_number_output = __( \' — No Repsonses\', \'text_domain\' );
        } else {
            $comments_number_output = sprintf(
                /* translators: number of comments */
                _nx(
                    \' — %1$s Response\',
                    \' — %1$s Responses\',
                    $comments_number,
                    \'comments title\',
                    \'text_domain\'
                ),
                number_format_i18n( $comments_number )
            );
        }
        $output .= $indent . sprintf(
            \'<li class="%s"><a href="%s">%s%s%s%s</a>\',
            $css_classes,
            get_permalink( $page->ID ),
            $args[\'link_before\'],
            /** This filter is documented in wp-includes/post-template.php */
            apply_filters( \'the_title\', $page->post_title, $page->ID ),
            $args[\'link_after\'],
            sprintf( \'<span class="comment-count">%s</span>\', // Append comment count.
                $comments_number_output
            )
        );

        if ( ! empty( $args[\'show_date\'] ) ) {
            if ( \'modified\' == $args[\'show_date\'] ) {
                $time = $page->post_modified;
            } else {
                $time = $page->post_date;
            }

            $date_format = empty( $args[\'date_format\'] ) ? \'\' : $args[\'date_format\'];
            $output .= " " . mysql2date( $date_format, $time );
        }
    }
}

然后在模板中，调用wp_list_pages() 像这样：

<ul><?php
    wp_list_pages( array(
        \'title_li\'    => \'\',
        \'depth\'       => 1,
        \'child_of\'    => get_the_ID(),
        \'sort_column\' => \'post_title\',
        \'show_date\'   => \'modified\',
        \'date_format\' => $date_format,
        \'walker\'      => new WPSE_Walker_Page_Comment_Count(),
    ) );
?></ul>

注意，我使用get_the_ID(), 这比使用global$id 变量而且$date_format 从未在原始代码中定义。最重要的部分是添加$walker 参数，表示wp_list_pages() 使用自定义walker生成输出。

输出示例（格式清晰）：

<ul>
    <li class="page_item page-item-1090">
        <a href="http://example.com/parent-page/child-page-01/">Child Page 01<span class="comment-count">&nbsp;— 1 Response</span></a>
    </li>
    <li class="page_item page-item-1092">
        <a href="http://example.com/parent-page/child-page-02/">Child Page 02<span class="comment-count">&nbsp;— No Responses</span></a>
    </li>
    <li class="page_item page-item-1094 page_item_has_children">
        <a href="http://example.com/parent-page/child-page-03/">Child Page 03<span class="comment-count">&nbsp;— 2 Responses</span></a>
    </li>
    <li class="page_item page-item-1096">
        <a href="http://example.com/parent-page/child-page-04/">Child Page 04<span class="comment-count">&nbsp;— No Responses</span></a>
    </li>
    <li class="page_item page-item-1098">
        <a href="http://example.com/parent-page/child-page-05/">Child Page 05<span class="comment-count">&nbsp;— No Responses</span></a>
    </li>
</ul>