这可以通过以下方式完成：

wp_get_attachment_metadata();

wp_update_attachment_metadata();

您将获得它的元数据，并对其进行更改，然后保存它。您获得的$数据数组包含另一个名为sizes的数组，该数组包含连接到附件的所有不同大小的图像。

您希望在上载方便命名的图像时自动更新。我不太明白为什么值得这么做，但让我们看看。

这需要做一点，这可能不是最好的方式，但它会起作用，并会让你知道如何做。

// hooking in to the add_attachment action just like you did
add_action(\'add_attachment\', function ( $post_ID ) {
    // we need to work with the database
    global $wpdb;

    // get the attachment
    $post = get_post( $post_ID );

    // remove the _x2 suffix to help find the original
    $attachment_name = str_replace( \'_x2\', \'\', $post->post_title );

    // did this file have an _x2 suffix?
    $is_x2 = ( $attachment_name == $post->post_title ) ? FALSE : TRUE;

    // get the attachments extension
    $extension = pathinfo( $post->guid, PATHINFO_EXTENSION );

    // if there is a large file, it would be called:
    $large_file = $attachment_name . \'_large.\' . $extension;

    // time to see if we have a large file saved
    // wordpress stores the relative path from the uploads directory
    // we use a like query to find the file in any year/month subdir
    $result = $wpdb->get_row($wpdb->prepare(
        "SELECT * FROM $wpdb->postmeta
            WHERE meta_value LIKE %s",
        \'%\' . $wpdb->esc_like($large_file)
    ));

    // did we find a file?
    if( !empty( $result ) ) {
        // yep we found a file, get its meta
        $attachment_meta = wp_get_attachment_metadata( $result->post_id );

        // get meta data on the new file
        $meta = get_post_meta( $post->ID, \'_wp_attached_file\', TRUE );

        // manually read the size of the new image
        $upl = wp_upload_dir();
        $new_file = $upl[\'basedir\'] . \'/\' . $meta;
        $sizes = getimagesize( $new_file );

        // what should the thumbnail be called?
        // remember we checked if the file had the _x2 suffix before?
        $thumb_name = ( $is_x2 ) ? \'x2\' : \'thumb\';

        // time to add the new size to the meta data of the large file
        $attachment_meta[\'sizes\'][$thumb_name] = array(
            \'file\' => basename($post->guid),
            \'width\' => $sizes[0],
            \'height\' => $sizes[1],
            \'mime-type\' => $sizes[\'mime\']
        );

        // save the new meta data to the large file
        wp_update_attachment_metadata( $result->post_id, $attachment_meta );

        // now we delete all references to the new file that was uploaded
        // by manually deleting it from the database the file will be kept on disk
        // this step is optional, Wordpress will behave a bit funny when uploading if used
        $wpdb->query($wpdb->prepare(
            "DELETE FROM $wpdb->posts
                WHERE $wpdb->posts.ID = %d", 
            $post->ID
        ));

        $wpdb->query($wpdb->prepare(
            "DELETE FROM $wpdb->postmeta 
                WHERE $wpdb->postmeta.post_id = %d", 
            $post->ID
        ));        
    }
});

最后2个删除查询是可选的，您说过您不想在数据库中为新图像添加新条目，这些查询将删除新条目。Wordpress不喜欢删除这些引用，上传时会有点搞笑，但不会破坏任何东西。

现在，您可以像处理其他缩略图一样轻松地获取缩略图。假设您已将大文件作为特色图像附加到帖子：

global $post;

// the filename_large.jpg file
echo get_the_post_thumbnail($post->ID);

// the filename.jpg file
echo get_the_post_thumbnail($post->ID, \'thumb\');

// the filename_x2.jpg file
echo get_the_post_thumbnail($post->ID, \'x2\');

您可以使用保存新附件元数据的$thumb\\u name变量更改缩略图的调用。

无论您是否使用可选的删除查询，这都会起作用，如果您只是为了方便起见，那么我说不要使用查询。如果您确实不希望缩略图显示为单个图像，请使用它们。