在yii2中的kartik form builder中无法进行验证

我用三个字段创建了表单对象，启用了ajax验证。但是我想在文件输入中禁用ajax验证。它不起作用

<?php
    $form = ActiveForm::begin(['options' => ['enctype' => 'multipart/form-data'],
                'enableAjaxValidation' => true,
                'formConfig'=>['labelSpan'=>6],
                ]);
echo Form::widget([
                'model' => $model,
                'form' => $form,
                'columns' => 2,
                'attributes' => [
                'campaign_name' => ['type'=>Form::INPUT_TEXT,'enableAjaxValidation' => true,
                'options'=>['placeholder'=>'Enter campaign name']],
                'voiceFile' => ['type'=>Form::INPUT_WIDGET,
                'widgetClass'=>'kartik\file\FileInput',
                'enableAjaxValidation' => false,
                'options'=>[
                'options' => ['accept' => '.mp3,.wav,.ogg','placeholder'=>'Choose a Excel file'],'pluginOptions'=>['showPreview'=>true]
                ],
                ],]]);
echo Form::widget([
                'model' => $model,
                'form' => $form,
                'columns' => 2,
                'attributes' => [
                'description' => ['type'=>Form::INPUT_TEXT,'enableAjaxValidation' => true, 'options'=>['placeholder'=>'Enter descritption']],
                'Action' => ['type'=>Form::INPUT_RAW, 'value'=>Html::submitButton($model->isNewRecord ? 'Create' : 'Update', ['class' => $model->isNewRecord ? 'btn btn-success' : 'btn btn-primary','style'=>'margin-top:25px']),],]
                ]);
ActiveForm::end();
?>

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要禁用验证，必须使用

'enableClientValidation'=>false

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你能解释一下原因吗