WordPress删除文章时，文章内所上传到媒体库的图片等附件不会自动删除，占用了网站空间。通过下面几行代码实现在删除文章时自动删除缩略图以及图片附件，这样就不用手动去媒体库或者是服务器中寻找删除，准确而且效率高。

将下面代码添加到当前主题函数模板functions.php中：

//删除文章时删除图片附件
function delete_post_and_attachments($post_ID) {
	global $wpdb;

	//删除特色图片
	$thumbnails = $wpdb->get_results( "SELECT * FROM $wpdb->postmeta WHERE meta_key = '_thumbnail_id' AND post_id = $post_ID" );
	foreach ( $thumbnails as $thumbnail ) {
		wp_delete_attachment( $thumbnail->meta_value, true );
	}

	//删除图片附件
	$attachments = $wpdb->get_results( "SELECT * FROM $wpdb->posts WHERE post_parent = $post_ID AND post_type = 'attachment'" );
		foreach ( $attachments as $attachment ) {
		wp_delete_attachment( $attachment->ID, true );
	}
	$wpdb->query( "DELETE FROM $wpdb->postmeta WHERE meta_key = '_thumbnail_id' AND post_id = $post_ID" );
}
add_action('before_delete_post', 'delete_post_and_attachments');

这段代码会在删除文章时先执行函数内容，删除特色图片以及图片附件，如果在使用action delete_post而不是before_delete_post将导致删除文章后因媒体附件与文章关联已取消而无法正确删除。