image is not uploading in YII ActiveForm
<p>I am new to Yii. I am using this code</p>

<pre>


    &lt;?php $form = ActiveForm::begin(['options' => ['enctype' => 'multipart/form-data']]); ?>
    &lt;?= $form->field($model, 'description')->textarea(['rows' => 6]) ?>
    &lt;?= $form->field($model, 'image')->fileInput(['type' => 'file']) ?>

    &lt;?= Html::submitButton($model->isNewRecord ? 'Create' : 'Update', ['class' => $model->isNewRecord ? 'btn btn-success' : 'btn btn-primary']) ?>

</pre>

<p>When i try to print post data in my controller then image field is going blank;<br/>
If i print through <pre> $_FILES </pre> then file data is showing. 
<br/>
Please let me know how to get image in post method.</p>