我想在“about”页面及其子页面上显示一个特定的动态侧栏。From the codex, 我尝试了以下方法：

<?php 
  // Begin main loop
  if ( have_posts() ): while ( have_posts() ):
  the_post();

  // If about page and about child pages
  if ( is_page(\'about\') && $post->post_parent > 0 ) {
    dynamic_sidebar(\'about\');
  }

  else {
    dynamic_sidebar(\'general\');
  }

  // End loop
  endwhile;
  endif;
?>

这行不通。我错过了什么？

我也尝试了以下方法。这对祖父母和父母有效，但对孩子无效。

<?php

  if (is_page (17) || (17 == $post->post_parent ) ) {
    dynamic_sidebar(\'about\');
  }

  else {
    dynamic_sidebar(\'general\');
  }

?>

下面是一个子页面的post对象转储，使用<?php echo \'<pre>\' . print_r( $post, true ); ?>:

WP_Post Object
(
    [ID] => 382
    [post_author] => 1
    [post_date] => 2018-08-15 17:02:56
    [post_date_gmt] => 2018-08-15 16:02:56
    [post_content] => 
    [post_title] => Art
    [post_excerpt] => 
    [post_status] => publish
    [comment_status] => closed
    [ping_status] => closed
    [post_password] => 
    [post_name] => art
    [to_ping] => 
    [pinged] => 
    [post_modified] => 2018-10-22 12:39:27
    [post_modified_gmt] => 2018-10-22 11:39:27
    [post_content_filtered] => 
    [post_parent] => 378
    [guid] => http://domain.local/?page_id=382
    [menu_order] => 0
    [post_type] => page
    [post_mime_type] => 
    [comment_count] => 0
    [filter] => raw
)

if ( is_page( \'about\' ) || $about_page_id == $post->post_parent ) {