将类添加到Yii2 Bootstrap4 Nav小部件中的子菜单容器

Question

我使用的导航小部件在Yii2。我有一个下拉框作为导航菜单的一部分，但下拉框很长，超出了页面的底部，不滚动。为了解决这个问题，我尝试将预滚动类添加到子菜单容器中。尽管我尽了最大努力，但似乎还是无法成功。

在导航小部件的Yii手册中(https://www.yiiframework.com/extension/yiisoft/yii2-bootstrap/doc/api/2.0/yii-bootstrap-nav)在$Items公共属性下，它表示：

下拉选项：数组，可选，将传递给yii\bootstrap\Dropdown小部件的HTML选项。

我还查看了下拉小部件的手册页(https://www.yiiframework.com/extension/yiisoft/yii2-bootstrap/doc/api/2.0/yii-bootstrap-dropdown).

我的导航小部件的代码如下：

echo Nav::widget([
    'options' => ['class' => 'navbar-nav ml-auto'],
    'items' => [
        ['label' => 'Home', 'url' => ['/site/index']],
        ['label' => 'About', 'url' => ['/site/about']],
        [
            'label' => 'Dropdown menu',

            //'dropDownOptions' => ['options' => ['class' => 'pre-scrollable']],
            //'dropDownOptions' => ['class' => 'pre-scrollable'],
            //'dropDownOptions' => ['submenuOptions' => ['class' => 'pre-scrollable']],
            //'submenuOptions' => ['class' => 'pre-scrollable'],
            //'submenuOptions' => ['options' => ['class' => 'pre-scrollable']],
            //'submenuOptions' => ['dropDownOptions' => ['class' => 'pre-scrollable']],
            //'dropDownOptions' => ['dropDownOptions' => ['class' => 'pre-scrollable']],
            //'submenuOptions' => ['submenuOptions' => ['class' => 'pre-scrollable']],
            //'options' => ['submenuOptions' => ['class' => 'pre-scrollable']],
            //'options' => ['class' => 'pre-scrollable'],
            //'options' => ['dropDownOptions' => ['class' => 'pre-scrollable']],

            'items' => [
                ['label' => 'Dropdown menu item 1', 'url' => '#'],
                ['label' => 'Dropdown menu item 2', 'url' => '#'],
                ...
            ],
        ],
        ['label' => 'Contact', 'url' => ['/site/contact']],
    ],
]);

注释掉的行是我试图“将超文本标记语言选项传递给yii\bootstrap\Dropdown小部件”的一些不同方式（按照越来越绝望的顺序）。

有人能帮我纠正一下吗？

期待中的感谢！

Answer 1

选项dropdownpoptions已在Yii 2.0版上成功测试。11.2和引导v3。3.7:

'dropDownOptions' => ['class' => 'pre-scrollable'],

结果是包含子菜单项的附加标记类

<ul id="w4" class="pre-scrollable dropdown-menu">

如果您使用的是yii2-bootstrap4，则该选项显然重命名为dropdownpoptions。

请参见源代码中的Nav:：renderDropdown（）：

/**
 * Renders the given items as a dropdown.
 * This method is called to create sub-menus.
 * @param array $items the given items. Please refer to [[Dropdown::items]] for the array structure.
 * @param array $parentItem the parent item information. Please refer to [[items]] for the structure of this array.
 * @return string the rendering result.
 * @throws \Exception
 */
protected function renderDropdown($items, $parentItem)
{
    /** @var Widget $dropdownClass */
    $dropdownClass = $this->dropdownClass;
    return $dropdownClass::widget([
        'options' => ArrayHelper::getValue($parentItem, 'dropdownOptions', []),
        'items' => $items,
        'encodeLabels' => $this->encodeLabels,
        'clientOptions' => false,
        'view' => $this->getView(),
    ]);
}

https://github.com/yiisoft/yii2-bootstrap4/blob/219d19fba47b5499f01764789c3cd3ce7306e0f9/src/Nav.php#L207