ESSAY / NOTE
AJAX与PHP通讯的黄金价格波动模拟更新实例
这个价格是从php中用rand函数随机生成的 仅供参考
回调获取json数据并且处理
glodPrice.php界面
<html>
<head>
<meta http-equiv="content-type" content="text/html;charset=utf-8"/>
<link href="Untitled-1.css" rel="stylesheet" type="text/css" />
<script src="my.js" type="text/javascript"></script>
<script type="text/javascript">
var myXmlHttpRequest;
function updateGoldPrice(){
myXmlHttpRequest=getXmlHttpObject();
if(myXmlHttpRequest){
//创建ajax引擎成功
var url="glodPriceProcess.php";
var data="city[]=dj&city[]=tw&city[]=ld";
myXmlHttpRequest.open("post",url,true);
myXmlHttpRequest.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
myXmlHttpRequest.onreadystatechange=function chuli(){
//接收数据json
if(myXmlHttpRequest.readyState==4){
if(myXmlHttpRequest.status==200){
//取出并转成对象数组
var res_objects=eval("("+myXmlHttpRequest.responseText+")");
$('dj').innerText=res_objects[0].price;
$('tw').innerText=res_objects[1].price;
$('ld').innerText=res_objects[2].price;
}
}
}
myXmlHttpRequest.send(data);
}
}
//使用定时器 每隔5 秒
window.setInterval("updateGoldPrice()",5000);
</script>
</head>
<center>
<h1>每隔5秒中更新数据(以1000为基数计算涨跌)</h1>
<table border=0 class="abc">
<tr><td colspan="3"><img src="gjhj_bj_tit.gif" /></td></tr>
<tr ><td>市场</td><td>最新价格$</td><td>涨跌</td></tr>
<tr><td>伦敦</td><td id="ld">788.7</td><td><img src="down.gif" />211.3</td></tr>
<tr><td>台湾</td><td id="tw">854.0</td><td><img src="down.gif" />146.0</td></tr>
<tr><td>东京</td><td id="dj">1791.3</td><td><img src="up.gif" />791.3</td></tr>
</table>
</center>
</html>
glodPriceProcess.php
<?php
//这里两句话很重要,第一讲话告诉浏览器返回的数据是xml格式
header("Content-Type: text/html;charset=utf-8");
//告诉浏览器不要缓存数据
header("Cache-Control: no-cache");
//接收
$cities=$_POST['city'];
//随机的生成 三个 500-2000间数
//$res='[{"price":"400"},{"price":"1000"},{"price":"1200"}]';
$res='[';
for($i=0;$i<count($cities);$i++){
if($i==count($cities)-1){
$res.='{"cityname":"'.$cities[$i].'" ,"price":"'.rand(500,1500).'"}]';
}else{
$res.='{"cityname":"'.$cities[$i].'" ,"price":"'.rand(500,1500).'"},';
}
}
file_put_contents("d:/mylog.log",$res."\r\n",FILE_APPEND);
echo $res;
?>