因功能需求，需要用到联动，特此记录分享

一、视图中

<div class="main-form">    <?php $form = ActiveForm::begin(); ?>    <?= $form->field($model, 'cid')->dropDownList(        \common\models\service\common\Category::getCateOptions(),        [            'prompt' => '请选择单位',            'onchange'=>'                $.post("/carousel/main/cate?id='.'"+$(this).val(),function(data){                    $("select#main-aid").html(data);                });',        ]    )->hint('父级，必选') ?>    <?= $form->field($model, 'aid')->dropDownList( \common\models\service\common\Category::getCateOptions(), ['prompt' => '请选择子级']) ?>    <div class="form-group">        <?= Html::submitButton('Save', ['class' => 'btn btn-success']) ?>    </div>    <?php ActiveForm::end(); ?></div>

二、控制器

ublic function actionCate($id){    $departments = Category::find()        ->where(['parent_id' => $id])        ->asArray()        ->all();    if(!$departments){        echo "<option value='" . 0 . "'>"  . "</option>";    }    foreach ($departments as $department) {        echo "<option value='" . $department['id'] . "'>" . $department['name'] . "</option>";    }}

三、实现效果

原文地址：