WordPress在导航栏加入搜索框

// ADD SEARCH BOX TO NAVIGATION
function so_add_search_box($items, $args) {
    ob_start();
    get_search_form();
    $searchform = ob_get_contents();
    ob_end_clean();
    $items .= '<li class="nav_search">' . $searchform . '</li>';
    return $items;
}
add_filter( 'wp_nav_menu_items','so_add_search_box', 10, 2 );
// END ADD SEARCH BOX