<?php 

//分页类

class page{

    private $total_rows; //总条数

    private $onepage_rows;//一页显示数量

    private $total_page; //总页数

    private $page_rows; //页码数量

    private $start_id;//描述起始ID

    private $end_id;//描述结束ID

    private $desc = ''; //描述上一页,下一页

    private $self_page; //当前页

    private $url;

    public function __construct($total,$onepage_rows=10,$page_rows=5,$desc=''){

        $this->total_rows = $total;

        $this->onepage_rows = $onepage_rows;

        $this->page_rows = $page_rows;

        $this->total_page = ceil($this->total_rows / $this->onepage_rows);

        $this->self_page = min(max((int)@$_GET['page'],1),$this->total_page);

        $this->start_id= ($this->self_page-1)*$this->onepage_rows+1;

        $this->end_id= min($this->self_page*$this->onepage_rows , $this->total_rows);

        $this->desc = $this->desc($desc); //上一页 下一页 共X条记录等信息

        $this->url = $this->requestUrl(); //URL生成

    }

    private function requestUrl(){

        $url =isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : $_SERVER['PHP_SELF'].'?'.$_SERVER['QUERY_STRING'] ;

        $parse_url = parse_url($url);

        if(isset($parse_url['query'])){

            parse_str($parse_url['query'],$arr);

            unset($arr['page']);

            $url =  $parse_url['path'] .'?'.http_build_query($arr).'&page=';

        }else{

            $url = strstr($url,'?') ?  $url.'page=' :$url. '?page=';

        }    

        return $url;

    }

    //指定列表页码

    public function pagelist(){  

        $start=max(1,min($this->self_page-ceil($this->page_rows/2),$this->total_page-$this->page_rows));

        $end=$start + $this->page_rows;

        $arr = array();

        for($i=$start; $i<=$end; $i++){

            if($i == $this->self_page){

                $arr[$i]['url'] = '';

                $arr[$i]['str'] = $i;

                continue;

            }

            $arr[$i]['url'] = $this->url.$i;

            $arr[$i]['str'] = $i;

        }

        return $arr;

    }

    //返回代码列表的字符串表示

    public function pageshow(){

        $pagelist = $this->pagelist();

        $pagestr = '';

        foreach($pagelist as $v){

            if(empty($v['url'])){

                $pagestr .= '<strong>'.$v['str'].'</strong>';

                continue;

            }

            $pagestr .= "<a href='".$v['url']."'>".$v['str']."</a>";

        }

        return $pagestr;

    }

    public function desc($desc){

        $d = array('prev' => '上一页','next' => '下一页','first'=> '首页','last' => '末页');

        if(empty($desc) || !is_array($desc)){ return $d;}

        function filter($v){

            return !empty($v);

        }

        return array_merge($d,array_filter($desc,'filter'));

    }

     //首页

    public function first(){

        return $this->self_page > 1 ? '<a href="'.$this->url.'1">'.$this->desc['first'].'</a>':'';

    }     

    //末页

    public function last(){

        return $this->self_page < $this->page_rows ? '<a href="'.$this->url.$this->page_rows.'">'.$this->desc['last'].'</a>':'';

    }

    //上一页

    public function prev(){

        return $this->self_page > 1 ? '<a href="'.$this->url.($this->self_page-1).'">'.$this->desc['prev'].'</a>':'';

    }

    //下一页

    public function next(){

        return $this->self_page < $this->total_page ? '<a href="'.$this->url.($this->self_page+1).'">'.$this->desc['next'].'</a>':'';

    }

    //返回当前第X-X条

    public function nowpage(){

        return '当前第'.$this->self_page.'页 第'.$this->start_id.'——'.$this->end_id.'条';

    }

    public function limit(){

        return 'limit '.max(0,($this->self_page-1)*$this->onepage_rows).','.$this->onepage_rows;

    }

}

 ?>