php簡單分頁類

<?php 
/**
 * 分頁類
 * 2011/8/31
 * kcj
 * */ 
class Page{ 
    private  $total;     //查詢總的數據記錄  
    private  $page;      //當前第幾頁  
    //private  $pagesize;  //每頁顯示的條數  
    private  $pagenum;   //總共多少頁  
    private  $num;       //每頁顯示記錄的條數  
    private  $offset;    //從數據庫中取記錄的開始偏移數  
     
    function __construct($total,$page=1,$num=5){ 
        $this->total=$total; 
        $this->page=$page; 
        $this->num=$num; 
        $this->pagenum=$this->getPageNum(); 
        $this->offset=$this->getOffset(); 
    } 
    private function getPageNum(){ 
        return  ceil($this->total/$this->num); 
    } 
    private function getNextPage(){    //下一頁  
        if($this->page==$this->pagenum){ 
            return false; 
        }else { 
            return $this->page+1; 
        } 
    } 
    private  function getPrevPage(){ 
        if($this->page==1){            //上一頁  
            return false; 
        }else { 
            return $this->page-1; 
        } 
    } 
    private  function getOffset(){ 
        return  ($this->page-1)*$this->num; 
    } 
    private function getStartNum(){ 
        if ($this->total==0) { 
            return 0; 
        }else { 
            return $this->offset+1; 
        } 
    } 
    private  function getEndNum(){ 
        return min($this->offset+$this->num,$this->total); 
    } 
    public function getPageInfo(){ 
        $pageInfo=array( 
         "row_total"=>$this->total, 
         "row_num"  =>$this->num, 
         "page_num" =>$this->getPageNum(), 
         "current_page"=>$this->page, 
         "row_offset"=>$this->getOffset(), 
         "next_page"=>$this->getNextPage(), 
         "prev_page"=>$this->getPrevPage(), 
         "page_start"=>$this->getStartNum(), 
         "page_end" =>$this->getEndNum() 
        ); 
        return  $pageInfo; 
    } 
} 
?> 

摘自 chaojie2009的專欄