WP：获取the_excerpt链接以显示完整内容

Question

Im building a WP theme for the first time and i have a problem with the excerpt When i click the read more link i only see the post as excerpt and not at its full content.

here is my loop

   <?php

  if (have_posts()) :
  while (have_posts()) :
  the_post();
  ?>    

    <article class="artikel">

    <p class="datum_artikel"> <?php the_time('Y-m-j');?> </p>
    <h4 class="headline_artikel"> <?php the_title();?> </h4>        
    <div class="nyheten"> <?php the_excerpt(); ?> </div> 

</article>
 <?php
 endwhile;
 endif;
 ?>
 </section><!-- Nyheter slut -->

 <?php

 get_footer(); 
?>

And my code in function.php

function new_excerpt_more( $more ) {
return ' <a class="read-more" href="'. get_permalink( get_the_ID() )  '">' . 
 __('Läs mer>>', 'your-text-domain') . '</a>';
 }

 add_filter( 'excerpt_more', 'new_excerpt_more' );

Im missing something her, right?