事实上，我刚刚完成了一个需要在其提要中添加图像的网站的工作，因此我最终使用了以下内容：

function ba_post_image_feeds($content) {
    global $post,$posts;
    $first_img = \'\';
    ob_start();
    ob_end_clean();
    $output = preg_match_all(\'/<img.+src=[\\\'"]([^\\\'"]+)[\\\'"].*>/i\', $post->post_content, $matches);
    $first_img = $matches [1] [0];

    if(!empty($first_img)){   

        $content = \'<div>\' . $first_img . \'</div>\' . $content;
    }
    return $content;
}


add_filter(\'the_excerpt_rss\', \'ba_post_image_feeds\');
add_filter(\'the_content_feed\', \'ba_post_image_feeds\');

这是另一种方法。

function add_images_to_rss($var) {
    global $post;
    if(has_post_thumbnail($post->ID)) {
        $tid = get_post_thumbnail_id( $post->ID);
        $thumb = wp_get_attachment_image_src($tid, \'thumbnail\');
        $thumb_meta = wp_get_attachment_metadata($tid);
        $up = wp_upload_dir();
        print \'<enclosure type="\'.get_post_mime_type($tid).\'" length="\'.filesize($up[\'basedir\'].\'/\'.$thumb_meta[\'file\']).\'" url="\'.$thumb[0].\'" />\';
    }
}
/* Technically this format is RSS2 only */
//    add_action(\'rss_item\',\'add_images_to_rss\');
    add_action(\'rss2_item\',\'add_images_to_rss\');
//    add_action(\'rdf_item\',\'add_images_to_rss\');
//    add_action(\'atom_entry\',\'add_images_to_rss\');