<pre name="code" class="php"><?php
class Page {
public $total; //总数
public $pageSize = 10; //每页的条数
protected $page= 1; //默认当前页码
public function __construct($total,$pageSize='') {
$this->total = $total;
if ($pageSize > 0) {
$this->pageSize = $pageSize;
}
//当前页码
if (isset($_GET['page']) && ($_GET['page'] + 0) > 0) {
$this->page = $_GET['page'] + 0;
}
}
public function showPageData() {
if ($this->total <=0) {
return ''; //如果总条目<=0 直接返回空字符串
}
$cnt = ceil($this->total / $this->pageSize); //算总页数,进一取整
//根据当前页,算上一页,下一页
/*
分析url,有几种情况?
xx.php
xx.php?id=5
xx.php?page=3
xx.php?id=5&page=3
*/
//最终生成的URL里边必然有page=N
$url = $_SERVER['REQUEST_URI'];
$parse = parse_url($url); //把URL分析结果放在数组里
//print_r($parse);
//保证参数里边有page
if (!isset($parse['query'])) {
$parse['query'] = 'page=' .$this->page;
}
//把query字符串分析成数组,再次确保有page选项
parse_str($parse['query'],$parms);
if (!array_key_exists('page', $parms)) {
$parms['page'] = $this->page;
}
//上边四种情况都测试一遍,page参数都能生成
//print_r($parms);
//判断除了page之外,还有没有其他参数
if (count($parms) == 1) {
$url = $parse['path'] . '?';
} else {
unset($parms['page']);
$url = $parse['path'] . '?' . http_build_query($parms) . '&';
}
//echo $url
$prev = $this->page - 1;
$next = $this->page + 1;
//首页
$indexLink = '<a href="' . $url .'page=' . 1 . '">首页</a>';
//上一页
if ($prev < 1) {
$prevLink = '';
}else {
$prevLink = '<a href="' . $url .'page=' . $prev . '">上一页</a>';
}
//下一页
if ($next > $cnt) {
$nextLink = '';
}else {
$nextLink = '<a href="' . $url .'page=' . $next . '">下一页</a>';
}
//尾页
$lastLink = '<a href="' . $url .'page=' . $cnt . '">尾页</a>';
$start = $this->page - (5-1)/2; //计算左侧开始的页码
$end = $this->page + (5-1)/2; //计算右侧开始的页码
//如果左侧的页面,已经小于1,则把小于1 的部分补到右侧
if ($start < 1) {
$end += (1 - $start);
$start = 1; //修改start = 1
if ($end > $cnt) {
$end = $cnt;
}
}
//把右侧超出的部分,补到左边
if ($end > $cnt) {
$start -= ($end - $cnt);
$end = $cnt;
if ($start < 1) {
$start = 1;
}
}
//循环出页码数
$pageStr = '';
for ($i=$start; $i <= $end ; $i++) {
if ($i == $this->page) {
$pageStr .= $i;
continue;
}
$pageStr .= '<a href="' . $url . 'page=' . $i . '">' . $i . '</a>';
}
return $indexLink.$prevLink.$pageStr.$nextLink.$lastLink;
}
}
$page = new Page(30,3);
echo $page->showPageData();
?>