如何在ActiveForm Yii2中制作自动加载域

class MyFormModel extends \yii\base\Model
{
    public $autoLoadField;
    
    // ...
}

use yii\widgets\ActiveForm;

$form = ActiveForm::begin();

echo $form->field($model, 'autoLoadField')->textInput();

// ...

ActiveForm::end();

public function actionSubmit()
{
    $model = new MyFormModel();
    
    if ($model->load(Yii::$app->request->post()) && $model->validate()) {
        // 处理自动加载域的值
        $autoLoadFieldValue = $model->autoLoadField;
        
        // ...
    }
    
    // ...
}