命名空间: ~~~ builder\widget\ajax ~~~ ```php WidgetFacade::echo2Return(function () { echo ButtonDropdown::widget([ 'label' => 'Action', 'dropdown' => [ 'items' => [ ['label' => 'DropdownA', 'url' => '/'], ['label' => 'DropdownB', 'url' => '#'], ], ], ]); }); ```