php生成翻页链接列表函数

/**
* 生成页码列表
*
* @author qifei
* @param int $element_total_count 元素总数
* @param int $current_page 当前页
* @param int $per_page_elem_count 每页元素数
* @param int $show_page_num 列表显示的页码数
* @param string $up_down_class 上下翻页样式
* @param string $num_class 当前页页码数字样式
* @param string $href 页面链接
* @param string $page_symbol 传递页码数的链接参数
* @return string
*/
function get_page_link_list($element_total_count,$current_page=1,$per_page_elem_count=10,$show_page_num=10,$up_down_class,$num_class,$href,$page_symbol='p')
{
if(empty($href))
{
//自动取得剔除页码参数的页面链接
$page_name = basename($_SERVER['PHP_SELF']);
$params = $_SERVER['QUERY_STRING'];
$params_str = '';
if(!empty($params))
{
$params = str_replace('&', '&', $params);
$params_array = explode('&', $params);
foreach($params_array as $param)
{
if(!empty($param))
{
$index = strpos($param, '=');
if($index)
{
$key = substr($param, 0, $index);
if($key && $key != $page_symbol)
$params_str .= $param . '&';
}
}
}
}
if(!empty($params_str))
$href = $page_name . '?' . $params_str;
else
$href = $page_name;

$href = rtrim($href,'&');
}

$prefix = strpos($href,"?") ? "&" : "?";
$prefix .= $page_symbol;

$page_total_count = ceil($element_total_count/$per_page_elem_count);

if(intval($element_total_count)< 1 || !isset($element_total_count))
{
return '';
}

if($element_total_count <= $per_page_elem_count)
return '';

if($current_page>$page_total_count)
$current_page = 1;

if(strpos($href,"#"))
{
$label = substr($href,strpos($href,"#"));
$href = substr($href,0,strpos($href,"#"));
}

/* 生成页码 */
if($current_page > ceil($show_page_num/2))
{
$start = $current_page - ceil($show_page_num/2);
$end = (($current_page+ceil($show_page_num/2))<$page_total_count) ?
$current_page+ceil($show_page_num/2)-1 : $page_total_count;
}
else
{
$start = 1;
$end = ($show_page_num>$page_total_count) ? $page_total_count : $show_page_num;
}

if(!empty($num_class))
$num_class_str = ' class="'.$num_class.'"';
else
$num_class_str = '';

$page_num_string = '';

for($i=$start;$i<=$end;$i++)
{
if(intval($i) == intval($current_page))
$page_num_string .= '<a'.$num_class_str.'>'.$i.'</a>';
else
$page_num_string .= '<a href="'.$href.$prefix.'='.$i.$label.'">'.$i.'</a>';
}

/* 上下翻页 */
$prev_page = (intval($current_page-1)>0)?intval($current_page-1):0;
$next_page = (intval($current_page)<$page_total_count) ? intval($current_page+1) : 0;

if(!empty($up_down_class))
$up_down_class_str = ' class="'.$up_down_class.'"';
else
$up_down_class_str = '';

$page_up_string = '';

if(intval($prev_page) > 0)
$page_up_string = '<a href="'.$href.$prefix.'='.$prev_page.$label.'"'.$up_down_class_str.'>上一页</a>';
else
$page_up_string = '<a'.$up_down_class_str.'>上一页</a>';

$page_down_string = '';

if(intval($next_page) > 0)
$page_down_string .= '<a href="'.$href.$prefix.'='.$next_page.$label.'"'.$up_down_class_str.'>下一页</a>';
else
$page_down_string .= '<a'.$up_down_class_str.'>下一页</a>';

/* 返回结果 */
return $page_up_string . $page_num_string . $page_down_string;
}