yii\data\Pagination::setPageSize PHP Method

    public function setPageSize($value, $validatePageSize = false)
    {
        if ($value === null) {
            $this->_pageSize = null;
        } else {
            $value = (int) $value;
            if ($validatePageSize && isset($this->pageSizeLimit[0], $this->pageSizeLimit[1]) && count($this->pageSizeLimit) === 2) {
                if ($value < $this->pageSizeLimit[0]) {
                    $value = $this->pageSizeLimit[0];
                } elseif ($value > $this->pageSizeLimit[1]) {
                    $value = $this->pageSizeLimit[1];
                }
            }
            $this->_pageSize = $value;
        }
    }

 public static function getPagedRows($query, $tablename, $params, $config = [])
 {
     $countQuery = clone $query;
     if (isset($params['SqlAttackSearch']) || isset($params['SqlLogSearch']) || isset($params['ErrorLogSearch'])) {
         //$rownums['nums'] = $countQuery->count();
         //在条件查询时不处理分页，给一个大概数
         $rownums['nums'] = 10000000;
     } else {
         $rownums = Yii::$app->db->createCommand("select TABLE_ROWS nums from information_schema.TABLES where TABLE_SCHEMA='Tuandai_Log' and TABLE_NAME='" . $tablename . "'")->queryOne();
     }
     $pages = new Pagination(['totalCount' => $rownums['nums']]);
     if (isset($config['pageSize'])) {
         $pages->setPageSize($config['pageSize'], true);
     }
     $rows = $query->offset($pages->offset)->limit($pages->limit);
     if (isset($config['orderBy'])) {
         $rows = $rows->orderBy($config['orderBy']);
     }
     $rows = $rows->all();
     $rowsLable = 'datas';
     $pagesLable = 'pager';
     if (isset($config['rows'])) {
         $rowsLable = $config['rows'];
     }
     if (isset($config['pages'])) {
         $pagesLable = $config['pages'];
     }
     $ret = [];
     $ret[$rowsLable] = $rows;
     $ret[$pagesLable] = $pages;
     return $ret;
 }