我创建了一个模板，但它没有输出任何内容

 <?php
/*
Template Name: Gallery
*/

get_header(); 


?>
<section>

    <div class="row">
        <div class="container">
            <ul>
                <?php if ( have_posts() ) : while ( have_posts() ) : the_post();    

                 $args = array(
                   \'post_type\' => \'attachment\',
                   \'numberposts\' => -1,
                   \'post_status\' => null,
                   \'post_parent\' => $post->ID
                  );

                  $attachments = get_posts( $args );
                     if ( $attachments ) {
                        foreach ( $attachments as $attachment ) {
                           echo \'<li>\';
                           echo wp_get_attachment_image( $attachment->ID, \'full\' );
                           echo \'<p>\';
                           echo apply_filters( \'the_title\', $attachment->post_title );
                           echo \'</p></li>\';
                          }
                     }

                 endwhile; endif; ?>
                </ul>
        </div>
    </div>
</section>
<?php get_footer();?>