如何每十秒刷新一次PHP脚本 - how do i refresh a php script every ten seconds?

我需要刷新一个php脚本每十秒，这是一个更新系统，它寻找任何新的更新，然后返回一个值javascript/php，然后在显示它们给用户在一个div?

如果不是，这是最好的方法吗?

我愿意接受所有的评论。

在JS函数中设置对php脚本的AJAX调用，函数的最后一行应该是setTimeout(functionname, 10000);

哦，你需要在某个地方第一次调用这个函数，然后它会继续运行…所以:

<html><head>
<script>
function update(){
//your ajax here
setTimeout(update,10000);
}
update();
</script></head>
<body><div id="theDivToUpdate"></div></body></html>

下面是一些示例代码，向您展示如何传递JSON或XML并让HTML页面处理它。下面是PHP(这里的数据只是硬编码的，但在您的情况下，您将动态填充):

<?php
$format=$_REQUEST['format'];
if($format=="json"){
    header('Content-type: application/json');
    header('Cache-Control: no-cache, must-revalidate');
    echo "{'"status'":'"ok'",'"results'":[{'"first'":'"MyFirst'",'"last'":'"MyLast'",'"company'":'"Big Company'"},{'"first'":'"YourFirst'",'"last'":'"YourLast'",'"company'":'"Another Company'"},{'"first'":'"John'",'"last'":'"Doe'",'"company'":'"What Company?'"},{'"first'":'"Jane'",'"last'":'"Doe'",'"company'":'"Stackoverflow'"}]}";
}
else if($format=="xml"){
    header("Content-type: text/xml");
    header('Cache-Control: no-cache, must-revalidate');
    echo "<ROOT><STATUS>ok</STATUS><RESULTS><RESULT><FIRST>MyFirst</FIRST><LAST>MyLast</LAST><COMPANY>Big Company</COMPANY></RESULT><RESULT><FIRST>YourFirst</FIRST><LAST>YourLast</LAST><COMPANY>Another Company</COMPANY></RESULT><RESULT><FIRST>John</FIRST><LAST>Doe</LAST><COMPANY>What Company?</COMPANY></RESULT><RESULT><FIRST>Jane</FIRST><LAST>Doe</LAST><COMPANY>Stackoverflow</COMPANY></RESULT></RESULTS></ROOT>";
    }
else{
    echo "You need to supply the ''format'' parameter (json or xml)";
}
?>

然后这里是一个示例HTML页面:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
<script>
function getJSON(){
        var xmlhttp;
        xmlhttp=((window.XMLHttpRequest)?new XMLHttpRequest():new ActiveXObject("Microsoft.XMLHTTP"));
        xmlhttp.onreadystatechange=function()
        {
          if (xmlhttp.readyState==4 && xmlhttp.status==200)
            {
                var res=xmlhttp.responseText; //THE JSON STRING IS TEXT
                res=JSON.parse(res);  //THIS CONVERTS THE JSON INTO OBJECTS THAT CAN BE ACCESSED WITH DOT NOTATION
                if(res.status=="ok"){
                    newtable="<table><tr><th>First</th><th>Last</th><th>Company</th></tr>";
                    for(i=0;i<res.results.length;i++){
                        newtable+="<tr><td>"+res.results[i].first+"</td><td>"+res.results[i].last+"</td><td>"+res.results[i].company+"</td></tr>";
                    }
                    newtable+="</table>";
                    document.getElementById('resultDiv').innerHTML=newtable;
                }
            }
        }
        xmlhttp.open("GET","thePHPFile.php?format=json",true);
        xmlhttp.send();
}
function getXML(){
        var xmlhttp;
        xmlhttp=((window.XMLHttpRequest)?new XMLHttpRequest():new ActiveXObject("Microsoft.XMLHTTP"));
        xmlhttp.onreadystatechange=function()
        {
          if (xmlhttp.readyState==4 && xmlhttp.status==200)
            {
                res=xmlhttp.responseXML;
                firstNameFields=res.documentElement.getElementsByTagName("FIRST"); //THESE LINES GRAB ALL OF THE NODES WITH THE INDICATED NAME AND HOLD THEM IN ARRAYS
                lastNameFields=res.documentElement.getElementsByTagName("LAST");
                companyFields=res.documentElement.getElementsByTagName("COMPANY");
                newtable="<table><tr><th>First</th><th>Last</th><th>Company</th></tr>";
                for(i=0;i<firstNameFields.length;i++){
                    newtable+="<tr><td>"+firstNameFields[i].firstChild.nodeValue+"</td><td>"+lastNameFields[i].firstChild.nodeValue+"</td><td>"+companyFields[i].firstChild.nodeValue+"</td></tr>";
                }
                newtable+="</table>";
                document.getElementById('resultDiv').innerHTML=newtable;
            }
        }
        xmlhttp.open("GET","thePHPFile.php?format=xml",true);
        xmlhttp.send();
}   
</script>
</head>
<body>
<input type="button" onclick="getJSON()" value="Retrieve and Parse JSON" />
<input type="button" onclick="getXML()" value="Retrieve and Parse XML" />
<div id="resultDiv"></div>
</body>
</html>

如果它显示在web浏览器中，我只需在setInterval()函数中执行ajax调用以轮询服务器以获取更新。刷新用JavaScript，而不是PHP