这里有一个我碰巧用过的。函数返回一个数组，该数组由作者ID数组、作者名称数组和作者数组成。

将此代码放入functions.php -

/**
 * Return an array of the number of posting authors, and their names and ID\'s
 */
function get_author_data(){

    global $wpdb;

    /** Create the query and then grab all of the ID\'s of all authors who have posted at least once */
    $query = $wpdb->prepare(\'SELECT DISTINCT %1$s.post_author FROM %1$s WHERE %1$s.post_status IN ("publish")\', $wpdb->posts);
    $author_ids = $wpdb->get_col($query);
    $authors[\'ID\'] = $author_ids;

    /** Get the name of all of the authors that have posted at least once */
    $authors[\'name\'] = array();
    if(!empty($authors[\'ID\'])) : foreach($authors[\'ID\'] as $author_id) :

            $query = $wpdb->prepare(\'SELECT %1$s.display_name FROM %1$s WHERE %1$s.ID = %2$s\', $wpdb->users, $author_id);
            $authors[\'name\'][] = $wpdb->get_var($query);

        endforeach;
    endif;

    /** Get a count of the number of authors who have posted at least once */
    $authors[\'count\'] = count($authors[\'ID\']);

    return $authors;

}

$authors = get_author_data();

/** Output all author names */
if(!empty($authors[\'name\'])) : foreach($authors[\'name\'] as $author_nam) :

        print_f(\'<li>%1$s</li>\', $author_name);

    endforeach;
endif;

/** Output a count of authors */
print_f(\'<p>Number of contributing authors: %1$s</p>\', $authors[\'count\']);