尝试以下操作：

<?php get_header(); ?>
<div id="content" class="clearfix row">     
<article id="post-<?php the_ID(); ?>" <?php post_class(\'clearfix\'); ?> role="article">
    <section id="work" class="row">      
        <div class="span3">
            <h3>Recent Work</h3>
            <p>Intro Lorem ipsum</p>
        </div>          
        <?php $args = array(
            \'post_type\'      => \'portfolio\',
            \'post_status\'    => \'publish\',
            \'posts_per_page\' => 3
        );
        $query = new WP_Query( $args );
        $porfolio_post_ids = array();
        if ( $query->have_posts() ) {
            while ( $query->have_posts() ) {
                global $post;
                $query->the_post();
                array_push( $porfolio_post_ids, $post->ID );
            }
        } ?>
        <div class="span6">
            <a href="<?php echo get_permalink( $porfolio_post_ids[0] ); ?>">
                <?php echo get_the_post_thumbnail(  
                    $porfolio_post_ids[0] , \'medium\' 
                ); ?> <!--Should be from custom post \'A\' -->
            </a>
        </div>   
        <div class="span3">
            <a href="<?php echo get_permalink( $porfolio_post_ids[1] ); ?>" >
                <?php echo get_the_post_thumbnail(  
                    $porfolio_post_ids[1] , \'thumbnail\' 
                ); ?><!--Should be from custom post \'B\' -->      
            </a>    
            <a href="<?php echo get_permalink( $porfolio_post_ids[2] ); ?>">
                <?php echo get_the_post_thumbnail( 
                    $porfolio_post_ids[2] , \'thumbnail\' 
                ); ?><!--Should be from custom post \'C\' -->
            </a>  
        </div>

我在你的代码中还注意到一件事：你说你的帖子类型是“公文包”，在你使用的永久链接中single-project.php, 但不是吗single-portfolio.php?

mattc，

您的问题是，所有元素都在循环中。您需要设置计数器，然后仅在需要时应用所需的项目。我只包含以下相关代码：

<?php 
 // set a variable to start a count
 $i = 0;

 $first_query = new WP_Query(\'post_type=portfolio\');   
 // the loop starts
 while($first_query->have_posts()) : $first_query->the_post(); 

 // add 1 to our variable on each pass of the loop
 $i++;

 // do the big image first
 if ($i == 1) {
 ?>
   <div class="span6">
        <a href="single-project.php">
        <?php the_post_thumbnail(\'medium\'); ?> <!--Should be from custom post \'A\' -->
        </a>
    </div>
 <?php } else { // the rest of the images ?>
 <?php if ($i == 2) {  // need to open our wrapping div here ?>
    <div class="span3">
 <?php } ?>
        <a href="single-project.php" >
         <?php the_post_thumbnail(\'thumbnail\'); ?><!--Should be from custom post \'B\' and \'C\' -->
        </a>
  <?php if ($i == 3) { // close out the wrapping div?>
    </div>
  <?php } ?>
  <?php endwhile; ?>

我很好地使用了这个实现--您可以看到它是如何抓住它的：

$thumbnails = get_posts(array(\'numberposts\'=>1,\'orderby\'=>\'ASC\',\'meta_key\' => \'_thumbnail_id\'));

然后，您可以转到“numberposts”=>3并构建缩略图结构：

    <?php if ( has_post_thumbnail() ) {
      global $post;
      $thumbnails = get_posts(array(\'numberposts\'=>3,\'orderby\'=>\'ASC\',\'meta_key\' => \'_thumbnail_id\'));
      foreach ($thumbnails as $thumbnail) {
      echo \'<a href="\' . get_permalink( $post->ID ) . \'" title="\' . esc_attr( $post->post_title ) . \'">\';
      echo get_the_post_thumbnail($thumbnail->ID, \'small-thumb\', array( \'alt\' => esc_attr( $post->post_title ), \'title\' => esc_attr( $post->post_title ) ));
      echo \'</a>\';
      }        
     ?>   

echo get_the_post_thumbnail($thumbnail->ID, \'small-thumb\', array( \'alt\' => esc_attr( $post->post_title ), \'title\' => esc_attr( $post->post_title ) ));

 //Add support, if you need it.
 if ( function_exists( \'add_theme_support\' ) ) {
   add_theme_support( \'post-thumbnails\' );
    set_post_thumbnail_size( 960, 276, true ); // default Post Thumbnail dimensions   
  }

 //Set them sizes, yo
 if ( function_exists( \'add_image_size\' ) ) { 
   add_image_size( \'large-thumb\', 960, 276, true ); //(cropped)
   add_image_size( \'medium-thumb\', 605, 174 ); // 605px wide, 174 high, not cropped
   add_image_size( \'small-thumb\', 288, 83, true ); //(cropped) 
   add_image_size( \'small-square\', 100, 100, true ); //(cropped) 
 }