php 翻页区间切割算法(翻页类)

    <style type="text/css">         #page a{margin:0 4px;padding:2px 8px;color:#666;border:#CCC 1px solid;  text-decoration: none;}        #page .cur,#page a:hover{padding:3px 9px;color:#fff;border:none;background:#a37e06;}   </style><?php/*** * 效果是百度分页那样的,不涉及数据库操作,* 实际上,分页的确是和数据库操作分开的* 使用方法* $total = 50;* $page = new Page($total);* echo $page->show(); */class Page {    public $total;  //总页数,在这里,你需要把总页数算出来    public $p;         //当前页数    public $start;     //排序起始页    public $end;       //排序终止页    public $url;      //当前的url,例如 index.php?p=    public $display;  //左边显示的页数,例如是5,就是说左边有5页,总共是10页    public function __construct($total, $url = '?p=', $display = '5') {        $this->total = $total;        $this->url = $url;        $this->display = $display;        $this->init();        $this->order();     }/**   *初始化,包括简单的安全处理,当然,你可以扩展这个函数以达到你的要求   */    public function init() {        //获取当前的页数        $this->p = (@$_GET['p'] + 0 <= 0)? 1: (@$_GET['p'] + 0);         if (!is_int($this->p)) {            $this->p = 1;         }        //如果有人在页面上输入一个较大的数,我是这样处理的,显示最后一页         //你可以自己扩展为"当前没有你找到的页",把下面的去掉,在show函数里加个判断就行了        if ($this->p >= $this->total) {            $this->p = $this->total;         }     }    /**      *这里将是怎么显示为百度分页的那种效果,当然,已经够用了      *还有局部没有处理好,如果处理好麻烦告诉我      */     public function order() {         if ($this->total <= 2 * $this->display) {            $this->start = 1;            $this->end = $this->total;         } else {             if ($this->p <= $this->display) {                $this->start = 1;                $this->end = 2 * $this->display;             } else {                 if ($this->p > $this->display && ($this->total - $this->p >= $this->display - 1)) {                    $this->start = $this->p - $this->display;                    $this->end = $this->p + $this->display - 1;                 } else {                    $this->start = $this->total - 2 * $this->display + 1;                    $this->end = $this->total;                 }             }         }     }     public function show() {        //如果没有数据,当然也就没有分页了        if ($this->total <= 0) {             return false;         }                $re = '<div id="page" >';          // $pre前一页 $next 后一页        $re .= "<a href=\"{$this->url}1\">首页</a> ";        $pre = ($this->p - 1 <= 0) ? 1 : ($this->p - 1);        $re .= "<a href=\"{$this->url}$pre\">前一页</a> ";        //如果当前页是第一页,不要首页和前一页        if ($this->p == 1) {            $re = '<div id="page" >';         }         for ($i = $this->start; $i <= $this->end; $i++) {            $re .= ($i == $this->p)? "$i ": "<a href=\"{$this->url}$i\">$i </a> ";         }          $next = ($this->p + 1 >= $this->total) ? $this->total : ($this->p + 1);        //当前页是最后一页的页数,不要下一页和最后一页        if ($this->p != $this->total) {            $re .= "<a href=\"{$this->url}$next\">下一页</a> ";            $re .= "<a href=\"{$this->url}$this->total\">最后一页</a>";         }            return $re;     }} $total = 50; $page = new Page($total); echo $page->show();?>