wordpress获取缩略图（特色图片）链接，并设置背景图片

<? if ( has_post_thumbnail( $recent["ID"]) ) { 
  $thumb_id = get_post_thumbnail_id($recent['ID']);
  $thumb_url = wp_get_attachment_image_src($thumb_id,'768*498', true);
  echo '<div class="bg-cover bg-center" style="height:385px;background-image: url('.$thumb_url[0].')"></div>';
}else{//没有则获取文章内首张图片链接
  echo '<div class="bg-cover bg-center" style="height:385px;background-image: url('.catch_first_image().')"></div>';
}
?>