结果发现有一个wp_nav_menu_objects 过滤器，允许您在将导航菜单项加入字符串之前修改它们的数组。我能够使用以下功能完成我需要的任务：

function wpse121517_add_shop_menu_links( $items, $args ) {

    if ( \'Shop Menu\' !== $args->menu )
        return $items;

    // Where to redirect after logging in or out
    $redirect = get_permalink( get_option( \'woocommerce_myaccount_page_id\' ) );

    $new_links = array();

    if ( is_user_logged_in() ) {
        $label = \'Logout\';
        $link = wp_logout_url( $redirect );

        // Create a nav_menu_item object to hold our link
        // for My Account, only if user is logged-in
        $item = array(
            \'title\'            => \'Account\',
            \'menu_item_parent\' => 0,
            \'ID\'               => \'my-account\',
            \'db_id\'            => \'\',
            \'url\'              => get_permalink( get_option( \'woocommerce_myaccount_page_id\' ) ),
            \'classes\'          => array( \'menu-item\' )
        );

        $new_links[] = (object) $item;  // Add the new menu item to our array
        unset( $item );
    } else {
        $label = \'Login\';
        $link = wp_login_url( $redirect );
    }

    // Create a nav_menu_item object to hold our link
    // for login/out
    $item = array(
        \'title\'            => $label,
        \'menu_item_parent\' => 0,
        \'ID\'               => \'loginout\',
        \'db_id\'            => \'\',
        \'url\'              => $link,
        \'classes\'          => array( \'menu-item\' )
    );

    $new_links[] = (object) $item; // Add the new menu item to our array
    $index = count( $items ) - 2;  // Insert before the last two items

    // Insert the new links at the appropriate place.
    array_splice( $items, $index, 0, $new_links );

    return $items;
}
add_filter( \'wp_nav_menu_objects\', \'wpse121517_add_shop_menu_links\', 10, 2 );