一个简单的AJAX实例
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <script> function loadXMLDoc() { var xmlhttp; if (window.XMLHttpRequest) { // IE7+, Firefox, Chrome, Opera, Safari 浏览器执行代码 xmlhttp=new XMLHttpRequest(); } else { // IE6, IE5 浏览器执行代码 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); } xmlhttp.onreadystatechange=function() { if (xmlhttp.readyState==4 && xmlhttp.status==200) { document.getElementById("myDiv").innerHTML=xmlhttp.responseText; } } xmlhttp.open("GET","/try/ajax/ajax_info.txt",true); xmlhttp.send(); } </script> </head> <body> <div id="myDiv"><h2>使用 AJAX 修改该文本内容</h2></div> <button type="button" onclick="loadXMLDoc()">修改内容</button> </body> </html>
用AJAX进行一次指定的head请求
<html><!DOCTYPE html> <html> <head> <script> function loadXMLDoc(url) { var xmlhttp; if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari xmlhttp=new XMLHttpRequest(); } else {// code for IE6, IE5 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); } xmlhttp.onreadystatechange=function() { if (xmlhttp.readyState==4 && xmlhttp.status==200) { document.getElementById('p1').innerHTML="Last modified: " + xmlhttp.getResponseHeader('Last-Modified'); } } xmlhttp.open("GET",url,true); xmlhttp.send(); } </script> </head> <body> <p id="p1">The getResponseHeader() function is used to return specific header information from a resource, like length, server-type, content-type, last-modified, etc.</p> <button onclick="loadXMLDoc('/try/ajax/ajax_info.txt')">Get "Last-Modified" information</button> </body> </html>
用AJAX从数据库返回数据
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <script> function showCustomer(str) { var xmlhttp; if (str=="") { document.getElementById("txtHint").innerHTML=""; return; } if (window.XMLHttpRequest) { // IE7+, Firefox, Chrome, Opera, Safari 浏览器执行代码 xmlhttp=new XMLHttpRequest(); } else { // IE6, IE5 浏览器执行代码 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); } xmlhttp.onreadystatechange=function() { if (xmlhttp.readyState==4 && xmlhttp.status==200) { document.getElementById("txtHint").innerHTML=xmlhttp.responseText; } } xmlhttp.open("GET","/try/ajax/getcustomer.php?q="+str,true); xmlhttp.send(); } </script> </head> <body> <form action=""> <select name="customers" onchange="showCustomer(this.value)" style="font-family:Verdana, Arial, Helvetica, sans-serif;"> <option value="APPLE">Apple Computer, Inc.</option> <option value="BAIDU ">BAIDU, Inc</option> <option value="Canon">Canon USA, Inc.</option> <option value="Google">Google, Inc.</option> <option value="Nokia">Nokia Corporation</option> <option value="SONY">Sony Corporation of America</option> </select> </form> <br> <div id="txtHint">客户信息将显示在这...</div> </body> </html>