瞧，我做到了（而且成功了）：

有什么区别（哪种代码更好）？

I tried this (see the last function):**

    /**
     * Description: Adds a taxonomy filter in the admin list page for a custom post type.
     * Written for: http://wordpress.stackexchange.com/posts/582/
     * By: Mike Schinkel - http://mikeschinkel.com/custom-workpress-plugins
     * Instructions: Put this code in your theme\'s functions.php file or inside your own plugin. Edit to suite your post types and taxonomies. Hope this helps...
    */
    add_filter(\'manage_listing_posts_columns\', \'add_businesses_column_to_listing_list\');
    function add_businesses_column_to_listing_list( $posts_columns ) {
        if (!isset($posts_columns[\'author\'])) {
            $new_posts_columns = $posts_columns;
        } else {
            $new_posts_columns = array();
            $index = 0;
            foreach($posts_columns as $key => $posts_column) {
                if ($key==\'author\') {
                $new_posts_columns[\'businesses\'] = null;
                }
                $new_posts_columns[$key] = $posts_column;
            }
        }
        $new_posts_columns[\'businesses\'] = \'Businesses\';
        return $new_posts_columns;
    }

    add_action(\'manage_posts_custom_column\', \'show_businesses_column_for_listing_list\',10,2);
    function show_businesses_column_for_listing_list( $column_id,$post_id ) {
        global $typenow;
        if ($typenow==\'listing\') {
            $taxonomy = \'business\';
            switch ($column_id) {
            case \'businesses\':
                $businesses = get_the_terms($post_id,$taxonomy);
                if (is_array($businesses)) {
                    foreach($businesses as $key => $business) {
                        $edit_link = get_term_link($business,$taxonomy);
                        $businesses[$key] = \'<a href="\'.$edit_link.\'">\' . $business->name . \'</a>\';
                    }
                    echo implode(\' | \',$businesses);
                }
                break;
            }
        }
    }

    /* JUST AN HYPOTHETICAL EXAMPLE
    add_action(\'manage_posts_custom_column\', \'manage_posts_custom_column\',10,2);
    function manage_posts_custom_column( $column_id,$post_id ) {
        global $typenow;
        switch ("{$typenow}:{$column_id}") {
        case \'listing:business\':
            echo \'...whatever...\';
            break;
        case \'listing:property\':
            echo \'...whatever...\';
            break;
        case \'agent:listing\':
            echo \'...whatever...\';
            break;
        }
    }
    */

    add_action(\'restrict_manage_posts\',\'restrict_listings_by_business\');
    function restrict_listings_by_business() {
        global $typenow;
        global $wp_query;
        if ($typenow==\'listing\') {
            $taxonomy = \'business\';
            $business_taxonomy = get_taxonomy($taxonomy);
            wp_dropdown_categories(array(
                \'show_option_all\' =>  __("Show All {$business_taxonomy->label}"),
                \'taxonomy\'        =>  $taxonomy,
                \'name\'            =>  \'business\',
                \'orderby\'         =>  \'name\',
                \'selected\'        =>  $wp_query->query[\'term\'],
                \'hierarchical\'    =>  true,
                \'depth\'           =>  3,
                \'show_count\'      =>  true,  // This will give a view
                \'hide_empty\'      =>  true,   // This will give false positives, i.e. one\'s not empty related to the other terms. TODO: Fix that
            ));
        }
    }

    add_filter(\'parse_query\',\'convert_business_id_to_taxonomy_term_in_query\');
    function convert_business_id_to_taxonomy_term_in_query($query) {
        global $pagenow;
        $qv = &$query->query_vars;
        if ($pagenow==\'edit.php\' &&
                isset($qv[\'taxonomy\']) && $qv[\'taxonomy\']==\'business\' &&
                isset($qv[\'term\']) && is_numeric($qv[\'term\'])) {
            $term = get_term_by(\'id\',$qv[\'term\'],\'business\');
            $qv[\'term\'] = $term->slug;
        }
    }

    add_action(\'init\',\'register_listing_post_type\');
    function register_listing_post_type() {
        register_post_type(\'listing\',array(
            \'label\' => \'Listings\',
            \'public\' => true,
            \'publicly_queryable\' => true,
            \'show_ui\' => true,
            \'query_var\' => true,
            \'rewrite\' => true,
            \'capability_type\' => \'post\',
            \'hierarchical\' => false,
        ));
    }

    add_action(\'init\',\'register_business_taxonomy\');
    function register_business_taxonomy() {
        register_taxonomy(\'business\',array(\'listing\'),array(
            \'label\' => \'Businesses\',
            \'public\'=>true,
            \'hierarchical\'=>true,
            \'show_ui\'=>true,
            \'query_var\'=>true
        ));
    }

    add_action(\'init\',\'insert_default_terms\');
    function insert_default_terms() {
      if (!get_option(\'site-page-content-initialized\')) {
        $terms = array(
          \'Intro (Front Page)\',
          \'Content (Front Page)\',
          \'Slider (Front Page)\',
          );
        foreach($terms as $term) {
          if (!get_term_by(\'name\',$term,\'business\')) {
            wp_insert_term($term, \'business\');
          }
        }
        update_option(\'site-page-content-initialized\',true);
      }
    }