php下封装较好的数字分页方法

/**
* 获取页码导航html
* @param $pagenum：当前页码
* @param $pagesize：每页数量
* @param $rowcount：记录总数
* @param $navurl：链接页面url
*/
function getnavhtml($pagenum,$pagesize,$rowcount,$navurl){
$pagecount = (int)($rowcount/$pagesize); //总页数
if ($rowcount % $pagesize >0){
$pagecount++;
}
if ($pagenum>$pagecount){
$pagenum = 1;
}
$firstnav = "<a href=\"{$navurl}page=1\">首页</a> ";
$lastnav = "<a href=\"{$navurl}page={$pagecount}\">尾页</a> ";
$prevnav="";
$nextnav="";
if ($pagenum>1){
$navpagenum = $pagenum-1;
$prevnav = "<a href=\"{$navurl}page={$navpagenum}\">上一页</a> ";
}
if ($pagenum<$pagecount && $pagecount>1){
$navpagenum = $pagenum+1;
$nextnav = "<a href=\"{$navurl}page={$navpagenum}\">下一页</a> ";
}
$amongnav="";

//关键循环

for ($i=1;$i<=5;$i++){
$navpagenum = $pagenum+ $i-3;
if ($navpagenum>0 && $navpagenum<=$pagecount){
$navcss = $navpagenum == $pagenum?" class=\"hover\"":"";
$amongnav.="<a href=\"{$navurl}page={$navpagenum}\" $navcss>{$navpagenum}</a> ";
}
}
return $firstnav.$prevnav.$amongnav.$nextnav.$lastnav." ".$pagenum."/".$pagecount." 共有[".$rowcount."]条数据";
}
}