新手分页有问题! [ 2.0 版本 ]

public  function  actionSel(){
       $title=\Yii::$app->request->post('title');
       $arr = Zk2::find()->where("title='$title'")->asArray()->one();
       $c_id=$arr['c_id'];
           $query = Zk2::find()->where("c_id='$c_id'");
           $countQuery = clone $query;
           $pages = new Pagination(['totalCount' => $countQuery->count()]);
           $pages->pageSize=2;
           $models = $query->offset($pages->offset)->limit($pages->limit)->asArray()->all();
      return $this->render('sel', ['models' => $models, 'pages' => $pages]);
}

然后点下一页报错?
Undefined index: title