另一个想法（这在很大程度上取决于您正在查看的[单个或归档]以及您的分类结构）是寻找术语父级。

也许这对你也有帮助。。。

您是在询问；特定职位层次结构中的最高类别；。

示例：
帖子与3 terms 分类法的hierachical:

Parent Term
-First-Child Term
--Second-Child Term

$all_terms = get_the_terms( $post_id, $taxonomy );

foreach($all_terms as $term) {

   if($term->parent == 0){
      //here you have the data of the topmost parent, e.g. "Parent Term"

      // get parent term ID
      $parent_id = $term->term_id; 

      // get term obj from ID to get term name
      $parent_obj = get_term_by( \'id\', $parent_id, $taxonomy );
      
      // show parent term name
      echo $parent_obj->name; // "Parent Term"

      // show parent term permalink URL
      echo = get_term_link( $parent_id );
   }

}

我想出来了。我在Wordpress中找不到这方面的任何核心功能，但要检索主要类别，可以使用get permalink函数：

$site_url = get_site_url();
$post_slug = get_permalink( $post_id );
$post_slug_remove_siteurl = str_replace( $site_url, \'\', $post_slug);                           
$category_from_slug = explode (\'/\', $post_slug_remove_siteurl);
$category_name = $category_from_slug[1];

<site-url> / <primary category> / <post name>

Display Primary Category (Yoast\'s WordPress SEO)

<?php
            // SHOW YOAST PRIMARY CATEGORY, OR FIRST CATEGORY
            $category = get_the_category();
            $useCatLink = true;
            // If post has a category assigned.
            if ($category) {
                $category_display = \'\';
                $category_link = \'\';
                if (class_exists(\'WPSEO_Primary_Term\')) {
                    // Show the post\'s \'Primary\' category, if this Yoast feature is available, & one is set
                    $wpseo_primary_term = new WPSEO_Primary_Term(\'category\', get_the_id());
                    $wpseo_primary_term = $wpseo_primary_term->get_primary_term();
                    $term = get_term($wpseo_primary_term);
                    if (is_wp_error($term)) {
                        // Default to first category (not Yoast) if an error is returned
                        $category_display = $category[0]->name;
                        $category_link = get_category_link($category[0]->term_id);
                    } else {
                        // Yoast Primary category
                        $category_display = $term->name;
                        $category_link = get_category_link($term->term_id);
                    }
                } else {
                    // Default, display the first category in WP\'s list of assigned categories
                    $category_display = $category[0]->name;
                    $category_link = get_category_link($category[0]->term_id);
                }
                // Display category
                if (!empty($category_display)) {
                    if ($useCatLink == true && !empty($category_link)) {
                        echo \'<span class="post-category">\';
                        echo \'<a href="\' . $category_link . \'">\' . htmlspecialchars($category_display) . \'</a>\';
                        echo \'</span>\';
                    } else {
                        echo \'<span class="post-category">\' . htmlspecialchars($category_display) . \'</span>\';
                    }
                }
            }
            ?>