ajax|计数器
这几天刚接触Ajax，写了一个非常简单的计数器。
客户端文件counter.htm用作模板，counter.php调用counter.htm模板。
当访问counter.php时，数据库记录ip、time，计数器加一。
XMLHttpRequest向counter_action.php发出请求，counter_action.php返回一个数字。
函数setTimeout()设置自动更新时间。
counter.htm清单
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>Ajax计数器</title>
<style type="text/css">...
<!--
.style2 {...}{
font-size: 16px;
color: red;
}
-->
</style>
<script type="text/javascript">...
var xmlHttp;
function createXMLHttpRequest()
...{
if (window.ActiveXObject)
...{
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
else if (window.XMLHttpRequest)
...{
xmlHttp = new XMLHttpRequest();
}
}
function doCount()
...{
createXMLHttpRequest();
var url = "counter_action.php";
xmlHttp.onreadystatechange = handleStateChange;
xmlHttp.open("GET", url, true);
xmlHttp.send(null);
}
function handleStateChange()
...{
if(xmlHttp.readyState == 4)
...{
if(xmlHttp.status == 200)
...{
var counter = document.getElementById("counter");
counter.innerHTML = xmlHttp.responseText+"次";
setTimeout("doCount()",10000);
}
}
}
</script>
</head>
<body >
<p align="center" class="style2">Ajax计数器</p>
<table width="300" border="0" align="center">
<tr>
<td><div align="center" id ="counter"></div></td>
</tr>
</table>
</body>
</html>
counter.php清单
<?php
include_once("./config/connect.php");
include_once("./private/functions.php");
$ip = getip(); //获取ip,函数定义在functions.php中
$time = time();
//访问数据库
$sql = "INSERT INTO `counter` VALUES (NULL,'$ip', '$time')";
$rs = $conn->Execute($sql);
//解析模板
$tpl->set_file("file","templates/counter.htm");
$tpl->parse("main","file");
$tpl->p("main");
$rs->Close();
$conn->Close();
?>
counter_action.php清单
<?php
include_once("./config/connect.php");
include_once("./private/functions.php");
//访问数据库
$sql = "SELECT * FROM `counter`";
$rs = $conn->Execute($sql);
$counter = $rs->rowcount();
$counter++;
echo $counter;
//释放数据库句柄
$rs->Close();
$conn->Close();
?>
