一个分页显示类

<?php
/*
 * 分页显示类
 * PageItem.php　v 1.0.0
  * 1. 配合MYSQL数据库使用
 * 2. 类没有提供连接数据库的功能，需在外部建立数据库连接。
 * */
/*
 * 使用方法：
 * $sql = "select * from news limit 0,10";
 * $hdc = new PageItem($sql);
 * echo $hdc->myPageItem();
 * $arrRecords = $hdc->ReadList();
 * */
if (!defined("__PAGEITEM__")) {
    define("__PAGEITEM__", 1);
} else {
    exit(3);
} 

class PageItem {
    var $iDefaultRecords = 10; // 默认每页显示记录数，如果没有设置，就使用默认值
    var $iMaxRecord; //每页记录数
    var $iTotal; //记录总数
    var $sqlRecord; // 获取记录的SQL查询
    var $iPages; //总页数
    var $CPages; //当前页数
    /*
  * 构造函数 －－ 初始化变量
  * 参数：SQL查询语句，将忽略LIMIT语句
  * */

    function PageItem($sql = "")
    { 
        // register_shutdown_function($this->_PageItem());
        $this->SetMaxRecord($this->iDefaultRecords);
        /*
       * 解析SQL语句
       * */
        if ($sql <> "") {
            list($sql) = spliti("LIMIT", $sql); // 去除LIMIT语句
            $this->sqlRecord = trim($sql);
            list(, $sql) = spliti("FROM", $sql);
            $sql = trim($sql);
   if(preg_match ("/\bGROUP\b \bBY\b/i", $sql))
   {
    //echo "HAVE GROUP BY";
    if(preg_match ("/\bHAVING\b/i", $sql)) list(,$field) = spliti("HAVING",$sql);
    list($field) = spliti(' ',trim($field));
    //echo $field;
    $this->iTotal = $this->CountRecord("SELECT $field,COUNT(DISTINCT $field) AS cnt FROM " . $sql,2);
   }
   else $this->iTotal = $this->CountRecord("SELECT COUNT(*) AS cnt FROM " . $sql,1);
        } 
        $this->iPages = ceil($this->iTotal / $this->iMaxRecord);
        $this->CPages = ＄＿REQUEST['page'];
if ($this->CPages <= 0) $this->CPages = 1;
if ($this->CPages > $this->iPages) $this->CPages = $this->iPages;
//echo "SELECT COUNT(*) AS cnt FROM " . $sql;
//echo $this->iTotal;
}
/*
* 析构函数 -- 暂时不可用
* */
function _PageItem()
{
// $this->linkid = NULL;
}
function SetMaxRecord($cnt)
{
$this->iMaxRecord = $cnt;
}
/*
* 统计匹配的记录总数
* */
function CountRecord($sql,$type)
{
//echo $sql;
if($type == 1)
{
if (($records = mysql_query($sql)) && ($record = mysql_fetch_assoc($records))) {
return $record['cnt'];
} else return 0;
}
elseif($type == 2)
{
if($records = mysql_query($sql))
return mysql_affected_rows();
}
}
/*
* 读取记录
* */
function ReadList()
{
$ret = array();
$this->sqlRecord.=" LIMIT ".($this->CPages-1)*$this->iMaxRecord.",".$this->iMaxRecord;
$records = mysql_query($this->sqlRecord);
if(!$records) return;
while($record = mysql_fetch_array($records))
{
$ret[] = $record;
}
return $ret;
}
function LinktoPage($page, $msg)
{
$link = $this->PageUrl($page);
return "<A href=\"$link\">$msg</A>\n";
}
function PageUrl($page)
{
$phpself = "http://" .＄＿SERVER['SERVER_NAME'] .＄＿SERVER['PHP_SELF'];
$querystring =＄＿SERVER['QUERY_STRING'];
$querystring = preg_replace("/page=[0-9]*&?/i", "", $querystring);
$link = $phpself . "?page=$page&" . $querystring;
return $link;
}
/*
* 显示当前页及总页数
* */
function PageNav()
{
echo "第" . $this->CPages . "页/共" . $this->iPages . "页";
}
/*
* 显示翻页按钮，包括首页、下页、上页、未页
* */
function PageButton()
{
if ($this->CPages > 1) {
echo $this->LinktoPage(1, "首页");
echo " | ";
echo $this->LinktoPage($this->CPages-1, "上一页");
} else {
echo "首页 | 上一页";
}
if ($this->CPages < $this->iPages) {
echo " | ";
echo $this->LinktoPage($this->CPages + 1, "下一页");
echo " | ";
echo $this->LinktoPage($this->iPages, "首页");
} else {
echo " | 下一页 | 尾页";
}
}
/*
* 显示跳转页选择框
* */
function SelectItem()
{
echo "跳到第<SELECT name='topage' size='1' onchange='window.location=this.value'>\n";
for($i = 1;$i <= $this->iPages;$i++) {
if ($this->CPages == $i)
$extra = "selected";
else
$extra = "";
echo "<OPTION VALUE='" . $this->PageUrl($i) . "' $extra>$i</OPTION>";
}
echo "</SELECT>\n";
}
/*
* 一次性显示所有按钮组件
* */
function myPageItem()
{
$this->PageButton();
$this->SelectItem();
$this->PageNav();
}
} // 类结束
?>