<?php

class mysqlPager
{
    var $pagePerNum = 5; //每页显示数据项数
    var $pagePerGroup = 5; //每分页组中页数
    var $curPage = 0; //当前页，Defualt 第一页
    var $totalPage = 0; //总页数
    var $totalNum = 0; //数据项总数
    var $curPageGroup = 0; //当前分页组
    var $curPageUrl = ""; //当前用到分页的 URL
    var $customStyle = ""; //自定义风格
    var $pageQuerySql = "";

    function mysqlPager()
    { //构造函数 PHP4
    }

    /**
     * 初始化所有变量
     */
    function InitAllVar($totalNum, $pagePerGroup, $curPageUrl, $curPage = 1, $curPageGroup = 1)
    {
        $this->totalNum = $totalNum;
        $this->pagePerGroup = $pagePerGroup;
        $this->curPageUrl = $curPageUrl;
        $this->curPage = $curPage;
        $this->curPageGroup = $curPageGroup;
    }

    /**
     * 设置当前页变量
     *
     * @param 数字 $curPage
     */
    function setCurPage($curPage)
    {
        $this->curPage = $curPage;
    }

    /**
     * 设置当前分页组变量
     *
     * @param mixed $curPageGroup
     */
    function setCurPageGroup($curPageGroup)
    {
        $this->curPageGroup = $curPageGroup;
    }

    /**
     * 设置当前用到分布类的URL
     * $curPageUrl string
     */
    function setCurPageUrl($curPageUrl)
    {
        $this->curPageUrl = $curPageUrl;
    }

    /**
     * 获取所有
     *
     * @param 数字 $totalNum
     * @param 数字 $curPage
     * @return float
     */
    function getTotalPage($totalNum, $curPage = 0)
    {
        return $this->totalPage = ceil($totalNum / $this->pagePerNum);
    }

    /**
     * 设置用户自定义风格
     *
     * @param mixed $customStyle
     */
    function setCustomStyle($customStyle)
    {
        $this->customStyle = $customStyle;
    }

    /**
     * 设置用户自定义风格返回字符串
     *
     *
     * @param mixed $pagerString
     */
    function setCustomStyleString($pagerString)
    {
        return $styleString = "<span class=" . $customStyle . ">" . $pagerString . "</span>";
    }

    /**
     * 输出导航页信息 可以不用参数，但是在使用前一定要设置相应的变量
     *
     * @param mixed $curPageGroup
     * @param mixed $curPage
     * @param mixed $curPageUrl
     */
    function showNavPager($curPageGroup = 0, $curPage = 0, $curPageUrl = 0)
    {
        if ($curPageGroup)
        {
            $this->curPageGroup = $curPageGroup;
        }
        if ($curPage)
        {
            $this->curPage = $curPage;
        }
        if ($curPageUrl)
        {
            $this->curPageUrl = $curPageUrl;
        }
        $rtnString = "";
//判断变量是否以经初始化 
        if ($this->curPageGroup && $this->curPageUrl && $this->totalNum && $this->curPage)
        {
            $this->totalPage = $this->getTotalPage($this->totalNum);
            if ($this->curPage == 1)
                $this->curPage = ($this->curPageGroup - 1) * $this->pagePerGroup + 1;
            if ($this->curPageGroup != 1)
            {
                $prePageGroup = $this->curPageGroup - 1;
                $rtnString .= "<a href=" . $this->curPageUrl . "?cpg=$prePageGroup >" . $this->setCustomStyleString("<<") . "</a> ";
            }
            for ($i = 1; $i <= $this->pagePerGroup; $i++)
            {
                $curPageNum = ($this->curPageGroup - 1) * $this->pagePerGroup + $i;
                if ($curPageNum <= $this->totalPage)
                {
                    if ($curPageNum == $this->curPage)
                    {
                        $rtnString .= " " . $this->setCustomStyleString($curPageNum);
                    } else
                    {
                        $rtnString .= " <a href=$this->curPageUrl?cpg={$this->curPageGroup}&cp=$curPageNum >";
                        $rtnString .= $this->setCustomStyleString($curPageNum) . "</a>";
                    }
                }
            }
            if ($this->curPageGroup < ceil($this->totalPage / $this->pagePerGroup) - 1)
            {
                $nextPageGroup = $this->curPageGroup + 1;
                $rtnString .= " <a href=$this->curPageUrl?cpg=$nextPageGroup >" . $this->setCustomStyleString(">>") . "</a>";
            }
            $this->pageQuerySql = " limit " . (($this->curPage - 1) * $this->pagePerNum) . "," . $this->pagePerNum;
        } else
        {
            $rtnString = "错误：变量未初始化！";
        }
        return $rtnString;
    }

    /**
     * 得到完整的查询MYSQL的Sql语句
     *
     * @param mixed $sql
     */
    function getQuerySqlStr($sql)
    {
        $allsql = $sql . $this->pageQuerySql;
        return $allsql;
    }

    /**
     * 设置每页有多少数据项
     *
     * @param INT $num
     */
    function setPagePerNum($num)
    {
        $this->pagePerNum = $num;
    }
}
$curPage=$_GET['cp'];
$curPageGroup=$_GET['cpg'];
if($curPage=="")
    $curPage=1;
if($curPageGroup=="")
    $curPageGroup=1;
//都是从1开始，之前要对传入的数据进行验证，防注入
//。。。
$pager=new MysqlPager();
$pager->initAllVar( )
$pager->showNavPager();
//后面的SQL可以是任意的输出
$sql="select id form dbname ";
$querysql=$pager->getQuerySqlStr($sql)
?>