分页类

class Page{
	private $total;
	private $listRows;
	private $limit;
	private $pageNum;
	private $config = array("header"=>"个记录","prev" =>"上一页","next"=>"下一页","first"=>"首页","last"=>"尾页");
	private $listNum = 8;	//显示的最大页数
	//$pa地址传参cid = 99
	public function __construct($total,$listRows=10,$pa ="",$listNum,$config){
		$this->total = $total;
		$this->listRows = $listRows;
		$this->uri =$this->getUri($pa);
		$this->listNum = $listNum;
		$this->config = $config;
		$this->page = !empty($_GET['page'])? $_GET['page']:1;
		$this->pageNum = ceil($this->total/$this->listRows);
		$this->limit =$this->setLimit();		
	}
	
	public function __get($args){
		if($args=="limit"){
			return $this->limit;
		}else{
			return null;
		}
	}
	
	private function setLimit(){
		return "Limit ".($this->page-1)*$this->listRows.", {$this->listRows}";
	}
	private function getUri($pa){
		
		/*
		$_SERVER['REQUEST_URI'] 域名后面的部分（除了'/'）
		strpos() 函数返回字符串在另一个字符串中第一次出现的位置。如果存在 ? 返回 '' 不然后面加上  ? 与含 '&cid =99' 的字符串相连组成一个字符串 
		parse_url() 将字符串解析成数组 $parse parse_atr() 会将$parse['query']?（?后面的参数）组合成一个数组 $params;销毁数组中的 page,$parse数组中的path与$params数组用http_build_query()函数生成一个URL-encode的字符串，返回没有page参数的url
		*/
		$url = $_SERVER['REQUEST_URI'].(strpos($_SERVER['REQUEST_URI'],'?')? '' : "?").$pa;
		$parse = parse_url($url);
		if(isset($parse['query'])){
			parse_str($parse['query'],$params);
			unset($params['page']);
			///http_build_query()  使用给出的关联（或下标）数组生成一个经过 URL-encode 的请求字符串
			$url =$parse['path'].'?'.http_build_query($params);
		}
		return $url;
	}
	private function start(){
		if($this->total ==0)
			return 0;
		else
			return ($this->page -1)*$this->listRows +1;			
	}
	private function end(){
		return min($this->page*$this->listRows,$this->total);
	}
	private function first(){
		if($this->page == 1){
			//$html .="<a>{$this->config['first']}</a>";
		}else{
			$html .= "<a href='{$this->uri}&page=1'>{$this->config["first"]}</a>";
		}
		return $html;
	}
	
	private function prev(){
		if($this->page ==1){
			//$html .="<a >{$this->config['prev']}</a>";
		}else{
			$html .="<a href='{$this->uri}&page=".($this->page -1)."'>{$this->config["prev"]}</a>";
		}
		return $html;
	}
	private function pageList(){
		$linkPage = '';
		$inum =floor($this->listNum/2);
		for($i =$inum; $i>=1 ;$i--){
			$page = $this->page-$i;
			if($page < 1){
				continue;
			}
			$linkPage .="<a href='{$this->uri}&page={$page}'>{$page}</a>";
		}
		$linkPage .="<a class='current'>{$this->page}</a>";
		for($i= 1;$i <= $inum ;$i++){
			$page = $this->page +$i;
			if($page <$this->pageNum){
				$linkPage .="<a href='{$this->uri}&page={$page}'>{$page}</a>";
			}else
				break;
		}
		return $linkPage;
	}
	private function next(){
		if($this->page == $this->pageNum){
			//$html .="<a>{$this->config["next"]}</a>";
		}else{
			$html .="<a href='{$this->uri}&page=".($this->page+1)."'>{$this->config["next"]}</a>";
		}
		return $html;
	}
	private function last(){
		if($this->page == $this->pageNum){
			//$html .="<a >{$this->config["last"]}</a>";
		}else{
			$html .= "<a href='{$this->uri}&page=".($this->pageNum)."'>{$this->config["last"]}</a>";
		}
		return $html;
	}
	
	function fpage($display = array(0,1,2,3,4,5,6,7,8)){
	  /*
	 $html[0]= "共有<b>{$this->total}</b>{$this->config["header"]}";
	 $html[1]= "每页显示<b>".($this->end()-$this->start()+1)."</b>条,本页<b>{$this->start}-{$this->end()}</b>条";
	 $html[2]= "<b>{$this->page}/{$tihs->pageNum}</b>页";
	 */
	$html[3]= $this->first();
	$html[4]= $this->prev();
	$html[5]= $this->pageList();
	$html[6]= $this->next();
	$html[7]= $this->last();
	//$html[8]= $this->goPage();	
		$fpage = "";
		foreach($display as $index){
			$fpage .=$html[$index];
		}
		return $fpage;
	}
}