这个plugin 使用添加内容the_content 优先级较低的筛选器：100。

因此，您可以创建一个输出元字段的函数，并使用具有更高优先级的相同过滤器，即使是标准的20优先级也很好。

function my_post_custom_data( $content ) {
  if ( ! is_single() ) return;
  global $post; 
  // here go the code that retrieve and append the custom field to the content
  // following is just an example
  $mydata = \'\';
  $a_field = get_post_meta($post->ID, \'a_key\', true) ? : \'\';
  $another_field = get_post_meta($post->ID, \'another_key\', true) ? : \'\';
  if ($a_field) $mydata .= \'<li>A key: \' . $a_field . \'</li>\';
  if ($another_field) $mydata .= \'<li>Another key: \' . $another_field. \'</li>\';
  $mydata = ($a_field || $another_field) ?  \'<div class="myfields"><ul>\' . $mydata . \'</ul></div>\' : \'\';
  // don\'t forget to return, at least, the content...
  return $content . $mydata;
}

add_filter(\'the_content\', \'my_post_custom_data\');