Get the attachment ID 对于图像，然后获取post meta字段_wp_attachment_metadata 为了它。这是一个序列化数组。现场sizes 该数组中包含所有可用的图像大小。

伪代码：

$sizes = array();

$attachment_url  = \'http://examle.com/wp-content-uploads/foo.png\';
$attachment_dir  = dirname( $attachment_url );
$attachment_id   = get_attachment_id( $attachment_url );
$attachment_meta = get_post_meta( $attachment_id, \'_wp_attachment_metadata\', TRUE );

$sizes[] = $attachment_url; // main file

if ( ! empty ( $attachment_meta[ \'sizes\' ] ) )
{
    foreach ( $attachment_meta[ \'sizes\' ] as $size )
        $sizes[] = "$attachment_dir/" . $size[ \'file\' ];
}