原生javascript ajax
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<div id="div" style="color:red"></div>
<input type="button" value="ajax" onclick="send_request()">
<script type="text/javascript">
function send_request() { //初始化、指定处理函数、发送请求的函数
http_request = false;
//开始初始化XMLHttpRequest 对象
if (window.XMLHttpRequest) {//Mozilla 浏览器
http_request = new XMLHttpRequest();
if (http_request.overrideMimeType) { //设置MiME 类别
http_request.overrideMimeType("text/plain");
//http_request.overrideMimeType("text/xml");
}
} else if (window.ActiveXObject) { // IE 浏览器
try {
http_request = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {
http_request = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) {
}
}
}
if (!http_request) { //异常，创建对象实例失败
window.alert("不能创建XMLHttpRequest对象实例.");
return false;
}
//指定回调处理函数
//方式一:
//http_request.onreadystatechange = processRequest;
// processRequest 是自定义的函数名 函数名称不加括号，不能指定参数
//方式二
//匿名函数
http_request.onreadystatechange = function () {
if (http_request.readyState == 4 && http_request.status == 200) {
var text = http_request.responseText;
document.getElementById('div').innerHTML = text;
}
}
//向服务器发出请求
//get 方式
/*var url = 'ajax.php?name=小明&age=20&sex=男';
http_request.open('GET',url);
http_request.send(null);*/
//post 方式
var url = 'ajax.php?name=小明&age=20&sex=男'; //$_GET['name']
var data = "year=2018&month=11"; //$_POST['year']
http_request.open('post', url, false); //false 异步
http_request.setRequestHeader("If-Modified-Since", 0);
http_request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");//open()的后面
http_request.send(data);
}
/**
* 回调函数
*/
function processRequest() {
if (http_request.readyState == 4 && http_request.status == 200) {
var text = http_request.responseText;
document.getElementById('div').innerHTML = text;
}
}
</script>
</body>
</html>ajax.php
<?php
//ajax.php
echo '现在时间是: '.date('Y-m-d H:i:s');
exit;
