使用 jQuery 实现网页局部自动刷新

原生 JavaScript 实现示例

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>ajax实现自动刷新</title>
</head>
<body onLoad="Autofresh()">
<p>现在的时间是：<span id="currenttime"></span></p>
  <script>
    var xmlobj;
    var count=0;
    function createXMLHttpRequest(){
      if(window.ActiveXObject){
        xmlobj=new ActiveXObject("Microsoft.XMLHTTP");
      }
      else if(window.XMLHttpRequest){
        xmlobj=new XMLHttpRequest();
      }
    }
    function Autofresh(){
      createXMLHttpRequest();    
       count=count+1;    
      xmlobj.open("GET","currenttime.php?count="+count,true);
      xmlobj.onreadystatechange=doAjax;
      xmlobj.send("r="+Math.random());//使用随机数处理缓存
    }
    function doAjax(){
      if(xmlobj.readyState==4 && xmlobj.status==200){
        var time_span=document.getElementById('currenttime');
        time_span.innerHTML=xmlobj.responseText;
        setTimeout("Autofresh()",2000);
      }
    }
  </script>
</body>
</html>

<?php
 $count=$_GET["count"];
 $count=$count%7;
  switch($count){
    case 1: $message = "11111111111111111";break;
    case 2: $message = "22222222222222222";break;
    case 3: $message = "33333333333333333";break;
    case 4: $message = "44444444444444444";break;
    case 5: $message = "55555555555555555";break;
    case 6: $message = "66666666666666666";break;
  }    
  $res = $message;
  echo date("Y-m-d H:i:s")."<hr>"."现在的内容是：".$res;
 ?>

jQuery 实现局部刷新

<script src="/js/jquery-1.3.2.min.js" type="text/javascript"></script> 

setInterval(function() {
  $("#content").load(location.href+" #content>*","");
}, 5000);