public function actionApplySuccess()
 {
     $activityUserId = Yii::$app->request->get('id');
     $activityUser = ActivityUsers::findOne(['id' => $activityUserId]);
     $maxCount = ActivityUsers::getMaxSignUpOrder($activityUser['activity_id']);
     $activityName = Activity::getOneActivityNameById($activityUser['activity_id']);
     $data = ['maxCount' => $maxCount, 'activityName' => $activityName];
     return $this->redirect(['/activity/apply-success', 'data' => $data]);
 }