public function actionAvatar()
    {
        $model = new AvatarForm();
        if ($model->load(Yii::$app->request->post()) && $model->save()) {
            Yii::$app->getSession()->setFlash('success', Yii::t('yuncms', 'Your avatar has been updated'));
        }
        return $this->render('avatar', [
            'model' => $model,
        ]);
    }