我正在尝试做一些看起来应该（也可能）简单的事情：显示高级自定义字段的结果get_field() 在返回shortcode函数时调用。

在主题模板中：

$posts = get_posts(array(
    \'posts_per_page\'    => -1,
    \'post_type\'         => \'produce\',
    \'orderby\'               => \'title\',
    \'order\'                 => \'ASC\'
  ));


  foreach( $posts as $post ):

    setup_postdata( $post );

    the_title(); 
    print_r(get_field(\'produce_image\')); 

然而，在短代码中，虽然WP_Post Objects包含在$posts 相同，the_title(); 返回调用短代码的页面的标题，以及get_field(\'produce_image\') 似乎没有返回任何内容，甚至没有返回空数组。

从中获取真实回报function_exists(\'get_field\').

整个短代码是：

<?php

function field_to_fork_produce_display( $atts ) {

  $atts = shortcode_atts(array(
    \'title\' => \'Produce\'
  ), $atts );

  $title = $atts[\'title\']; 

  /*
  $plugins_dir = plugin_dir_path( __file__ );
  $plugins_dir = str_replace("/field-to-fork/lib/", "", $plugins_dir);
  include_once($plugins_dir.\'/advanced-custom-fields/acf.php\'); 
  */    

  $result = \'<div class="col"><h2 class="text-center"><?=$title?></h2>\';

  $posts = get_posts( array(
    \'posts_per_page\'    => -1,
    \'post_type\'           => \'produce\',
    \'orderby\'                 => \'title\',
    \'order\'                   => \'ASC\'
  ));

  mz_pr($posts);

  if( $posts ): 
?>

<?php

    foreach( $posts as $post ):

      setup_postdata( $post );
      mz_pr(get_post_meta($post->ID, \'produce\', true));

?>
<?php 

      if ( has_post_thumbnail() ) { // check if the post has a Post Thumbnail assigned to it. 

        $result .=  \'<a href="<?php the_permalink(); ?>">\';
        the_post_thumbnail( \'thumb\', array( \'class\' => "img-responsive img-center"));

      }       

      $result   .=      \'</a>\';
      $result   .=      \'<h4><a href="<?php the_permalink(); ?>">\' . the_title() . \'</a></h4>\';
      $result   .=      \'<p>\' . the_excerpt() . \'</p>\';

      if ( ! function_exists( \'get_field\' ) ) {
        die(\'not there\');
      }

      mz_pr(function_exists(\'get_field\'));
      mz_pr(get_field(\'produce_image\')); 
      echo get_field(\'produce_image\');
      mz_pr("nothing to see here"); 

      $produce_thumbnail = get_field(\'produce_image\', false, false)[\'sizes\'][\'thumbnail\'];
      $result   .= \'<img src="<?=$produce_thumbnail?>" class="img-responsive field_to_fork_thumb <?php the_title(); ?>">\';
      $result   .=      \'</a>\';

    endforeach; 

    wp_reset_postdata(); 

  endif; 

  $result   .= \'</div><!-- end span 6-->\';

  return $result;
} 

?>