在视图中:
<?= Html::dropDownList("A",null,ArrayHelper::map(A::find()->asArray()->all(), 'id', 'name'),[
"class"=>"form form-control",
"prompt"=>Yii::t('template', 'Select anything ...'),
'onchange'=>'
$.get("route/to/action/A?param='.'"+$(this).val(),function(data){
$("select#idOfBSelct").html(data);
});'
]);?>
<?= Html::dropDownList("B",null,[],[
"class"=>"form form-control",
"id"=>"idOfBSelct",
"prompt"=>Yii::t('template', 'Select anything ...'),
]);?>
在控制器中:
public function actionA()
{
$dataFromAjax = Yii::$app->request->getQury('param');
// do something with $dataFromAjax what you want
return $anyResult;
}