我已经创建了一个幻灯片，可以自动填充帖子库中包含的图像，我还想显示每个图像的“标题”字段。

我当前正在使用get_post_gallery_images 循环浏览相关图像，但这只返回图像URL的数组，我需要标题数据。这个$counter 和$sizes 变量是一些额外的修饰符，用于处理Flexslider中的内容，但它们不是在图像中循环所必需的。

   function get_images($post_id) {
   global $post;

  if( has_shortcode( $post->post_content, \'gallery\' ) ) {
      $gallery = get_post_gallery_images( $post->ID ); // Returns array or URLs
      $counter = -1;
      $sizes = ["-300x200", "-200x300"]; // Search for medium suffixes from gallery thumbs

      // Loop through each image in each gallery
      foreach( $gallery as $image ) {

          $counter++;
          $attachment = get_post($image);

          echo \'<li>\';
          echo \'<img src=" \' . str_replace($sizes, \'\', $image) . \'"\';
          echo \' alt="\';
          echo \'" data-slide="\';
          echo $counter;
          echo \'" />\';
          echo \'</li><!--end slide-->\';
          echo \'<p class="slide-caption">\';
          echo \'</p>\';
      } // End for each
  } // End if

} // End function

我发现使用wp_prepare_attachment_for_js 但我认为这需要把图片附在帖子上。我想从gallery （无论图像是否附加到此特定帖子）因为我希望客户端能够通过媒体库上传，而无需担心附件。关于如何做到这一点，我有什么想法吗？还是我只需要接受附件是必要的？

Updated code based on answer — 对于任何试图从缩略图库构建Flexslider幻灯片的人。。。这包括计算每个图像的额外变量，并为其指定data-slide 数字（Flexslider用于编程链接）。下面的答案返回缩略图或库使用的任何大小的图像，因此我想出了一种方法来解析URL并删除大小声明以返回全尺寸图像。

// GALLERY WITH CAPTIONS
function slider_from_gallery($post_id) {
        if (
          $gallery = get_post_gallery( get_the_ID(), false ) ) :
              $img_ids = explode( \',\', $gallery[\'ids\'] );
              $counter = -1;
            /* Loop through all the image and output them one by one */
            foreach(
              $gallery[\'src\'] as $key => $src ) : ?>

                <li>
                  <?php
                  $image_post = get_post( $img_ids[ $key ] );
                  $counter++; // Increase for each image, gets passed to data-slide below
                  $new_src = substr($src, 0, strrpos( $src, \'-\')) . \'.jpg\'; // Get full size by finding last occurance of - and adding .jpg
                   ?>
                  <img src="<?php echo $new_src; ?>" class="slide-image" alt="Gallery image" data-slide="<?php echo $counter ?>" />
                  <p class="flex-caption"><?php echo $image_post->post_excerpt; ?></p>
                </li>

            <?php endforeach;
        endif;
} //End function

<?php $loop = new WP_Query( array( \'post_type\' => \'gallery\', 
        \'posts_per_page\' => 100 ) 
            ); 
        while ( $loop->have_posts() ) : $loop->the_post();

        if ( $gallery = get_post_gallery( get_the_ID(), false ) ) :

            $img_ids = explode( \',\', $gallery[\'ids\'] );
            /* Loop through all the image and output them one by one */
            foreach( $gallery[\'src\'] as $key => $src ) : ?>

                <img src="<?php echo $src; ?>" class="my-custom-class" alt="Gallery image" />
                <?php
                    $image_post = get_post( $img_ids[ $key ] ); ?>
                    <p class="wp-caption-text"><?php echo $image_post->post_excerpt; ?></p>

            <?php endforeach;
        endif;

 endwhile; wp_reset_postdata(); ?>