php相当简单的分页类

class helper_page{

/** 总信息数 */
var $infocount;
/** 总页数 */
var $pagecount;
/** 每页显示条数　*/
var $items;
/** 当前页码 */
var $pageno;
/** 查询的起始位置　*/
var $startpos;
/** 下一页　*/
var $nextpageno;
/** 上一页　*/
var $prevpageno;

function helper_page($infocount, $items, $pageno)
{
$this->infocount = $infocount;
$this->items = $items;
$this->pageno = $pageno;
$this->pagecount = $this->getpagecount();
$this->adjustpageno();
$this->startpos = $this->getstartpos();
}
function adjustpageno()
{
if($this->pageno == '' || $this->pageno < 1)
$this->pageno = 1;
if ($this->pageno > $this->pagecount)
$this->pageno = $this->pagecount;
}
/**
* 下一页
*/
function gotonextpage()
{
$nextpageno = $this->pageno + 1;
if ($nextpageno > $this->pagecount)
{
$this->nextpageno = $this->pagecount;
return false;
}
$this->nextpageno = $nextpageno;
return true;
}
/**
* 上一页
*/
function gotoprevpage()
{
$prevpageno = $this->pageno - 1;
if ($prevpageno < 1)
{
$this->prevpageno = 1;
return false;
}
$this->prevpageno = $prevpageno;
return true;
}
function getpagecount()
{
return ceil($this->infocount / $this->items);
}
function getstartpos()
{
return ($this->pageno - 1) * $this->items;
}
}