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;

}

}