每次上载新图像时afip_new_post_content 调用过滤器，可用于在创建之前更改帖子内容-http://wordpress.org/extend/plugins/automatic-featured-image-posts/

假设您有一个url列表存储在某个地方，比如数据库中，那么您需要一个从该列表中获取url的函数，然后从该列表中删除您使用的url，这样它就不会再次被使用。

function get_one_url(){
    /**
     * your urls would be stored somewhere I suppose. Everytime you get a url,
     * the number of URLs would decrease by one.
     */

    //this is just a sample. you could probably build this using a database call.
    $list_of_urls = array(
        "http://url1.com",
        "http://url2",
        "http://url3"
    );

    //get the first url off the list and save it to the variable $url
    $url = array_shift( $list_of_urls );

    //save new list to database. This is just a sample.
    save_my_list( $list_of_urls );

    return $url;
}


add_filter( \'afip_new_post_content\', \'diww_default_post_content\' );
function diww_default_post_content() {
    $url = get_one_url();
    $content = "<iframe src={$url}></iframe>";
    return $content;
}

?>