仿阿里巴巴同级产品翻页的实现

<?php/** 实现同类产品翻页 **/class pager{protected $space;protected $left;protected $DB;protected $pageName;public function setSpace($num) {$this->space = $num;$this->left = ceil(($num-1)/2);}public function setDB(&$db) {$this->DB = $db;}public function setPageName($pageName) {$this->pageName = $pageName;}public function getPages($catid, $exptime) {$fields = array("`id`,`title`");$left = array(">" => array("exptime"=>$exptime), "memberid" => gs(_MEM_PREFIX_ . "memberid"), "catid"=>$catid);$right = array("<" => array("exptime"=>$exptime), "memberid" => gs(_MEM_PREFIX_ . "memberid"), "catid"=>$catid);$leftCount = $this->DB->getCount($left);if($leftCount <= $this->left) {$star = 1;$leftLimit = "LIMIT" . $leftCount;$rightLimit = "LIMIT " . ($this->space-$leftCount);}else {$start = $leftCount - $this->left;$leftLimit = "LIMIT " . $this->left;$rightLimit = $leftLimit;}$list1 = $this->DB->findAll($left, array("exptime"=>"ASC"), $leftLimit, $fields);$list2 = $this->DB->findAll($right, array("exptime"=>"DESC"), $rightLimit, $fields);/** 上一页链接 **/$c = count($list1);if($c > 1) {$url = $this->pageName."-".$list1[$c]['id'].".html";$pages = "<a href="/" mce_href="/""{$url}/">上一页</a><ol>";}elseif($c == 1) {$url = $this->pageName."-".$list1[0]['id'].".html";$pages = "<a href="/" mce_href="/""{$url}/">上一页</a><ol>";}else {$pages = "";}/** 当前页的左边内容 **/foreach($list1 as $item) {$url = $this->pageName."-".$item['id'].".html";$pages .= "<li><a href="/" mce_href="/""{$url}/">{$start}</a></li>";$start++;}$pages .= "<li><b>{$leftCount}</b></li>";$start++;/** 当前页面右边的内容 **/foreach($list1 as $item) {$url = $this->pageName."-".$item['id'].".html";$pages .= "<li><a href="/" mce_href="/""{$url}/">{$start}</a></li>";$start++;}/** 下一页的链接 **/$c = count($list2);if($c > 0) {$url = $this->pageName."-".$list2[0]['id'].".html";$pages .= "<a href="/" mce_href="/""{$url}/">下一页</a><ol>";}else {$pages .= "";}return $pages;}};?>

$B = Factory::loadCommon("Brothers");$B->setSpace(9);$B->setPageName($pagename);$B->setDB($this->DB);$pp = $B->getPages($id, $product['memberid'], $product['catid']);$catTotal = $B->getTotal($product['memberid'], $product['catid']);$this->response->set("brothers", $pp);$this->response->set("catTotal", $catTotal); 

 

当前页左边的页码为最新的产品，按更新时间呈升序排列；右边的页码为早期的产品， 按更新时间呈降序排列。如果左边的记录条数小于$space(页码区段)的值，页码$start从1开始向右增值。如果左则的记录条数多于$left(左右各显示页数)的值，$start将从左边记录数减去$left值开始记数。