WordPress获取文章子元素函数：get_children

WordPress函数get_children可用于获取文章下的附件、子页面，通常我用来获取文章缩略图。

get_children( array $args = '', constant $output = OBJECT )

函数参数

$args

数组或字符串值

get_children()函数$args参数默认的值如下：

$defaults = array( 'numberposts' => -1, 'post_type' => 'any', 'post_status' => 'any', 'post_parent' => 0, );

get_children()函数$args参数可用的值如下：

numberposts

整数型，默认值：-1

指定返回信息的数量，默认不限制

post_parent

整数型，默认值：0

父元素的ID，指定一个文章ID，将返回该文章下的子元素

post_type

字符串值，默认值：any

指定文章类型，例如：attachment、page、revision，默认所有类型

post_status

字符串值，默认值：any

文章状态，例如：publish、draft、inherit

post_mime_type

字符串值，默认为空

指定文件的MIME类型，例如：image、video、video/mp4，在返回指定格式的附件时特别有用

函数返回值

Array ( [240] => WP_Post Object ( [ID] => 240 [post_author] => 1 [post_date] => 2014-07-25 09:27:19 [post_date_gmt] => 2014-07-25 01:27:19 [post_content] => [post_title] => baiduseo [post_excerpt] => [post_status] => inherit [comment_status] => open [ping_status] => closed [post_password] => [post_name] => baiduseo [to_ping] => [pinged] => [post_modified] => 2014-07-25 09:27:19 [post_modified_gmt] => 2014-07-25 01:27:19 [post_content_filtered] => [post_parent] => 239 [guid] => http://localhost/wp-content/uploads/2014/07/baiduseo.jpg [menu_order] => 0 [post_type] => attachment [post_mime_type] => image/jpeg [comment_count] => 0 [filter] => raw ) )

函数使用示例

返回ID为239的文章下的所有图片：

$images = get_children( 'post_parent=239&post_type=attachment&post_mime_type=image' );

获取文章第一张图片的缩略图：

<?php function echo_first_image( $postID ) { $args = array( 'numberposts' => 1, 'order' => 'ASC', 'post_mime_type' => 'image', 'post_parent' => $postID, 'post_status' => null, 'post_type' => 'attachment', ); $attachments = get_children( $args ); if ( $attachments ) { foreach ( $attachments as $attachment ) { echo '<img src="' . wp_get_attachment_thumb_url( $attachment->ID ) . '" class="current">'; } } } ?>

扩展阅读

get_children()函数位于：wp-includes/post.php