yii2 navbar with dropdown

Question

After some simple edit on the default navbar, I got the code for the menu below... It would be very ugly if I add more menus.

Answer 1

From the official documentation. I got the answer. I changed the options from nav-pills to navbar-nav

echo Nav::widget([
    'items' => [
        [
            'label' => 'Home',
            'url' => ['site/index'],
            'linkOptions' => [...],
        ],
        [
            'label' => 'Dropdown',
            'items' => [
                 ['label' => 'Level 1 - Dropdown A', 'url' => '#'],
                 '<li class="divider"></li>',
                 '<li class="dropdown-header">Dropdown Header</li>',
                 ['label' => 'Level 1 - Dropdown B', 'url' => '#'],
            ],
        ],
    ],
    'options' => ['class' =>'navbar-nav'],
]);

Answer 2

Well I don't have the reputation needed but, just to be more correct on the "nerison" answer, add the nav class too: like these

'options' => ['class' =>'nav navbar-nav'],