1、ajax对象(XMLHttpRequest和ActiveXObject) 2、如何兼容IE6浏览器
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>未封装请求</title>
<script>
window.onload = function () {
var oBtn = document.getElementById('btn1');
var div1 = document.getElementById('div1');
oBtn.onclick = function () {
//1.创建Ajax对象
if (window.XMLHttpRequest) { // 非IE6(undefinded)
var oAjax = new XMLHttpRequest();
} else { // IE6
var oAjax = new ActiveXObject("Microsoft.XMLHTTP");
}
//2.连接服务器
//open(方法, 文件名, 异步传输)
oAjax.open('GET', 'a.txt', true); // 读取a.txt
//3.发送请求
oAjax.send();
//4.接收返回
oAjax.onreadystatechange = function () {
//oAjax.readyState //浏览器和服务器,进行到哪一步了
if (oAjax.readyState == 4) //读取完成
{
if (oAjax.status == 200) //成功
{
div1.innerHTML = oAjax.responseText;
} else {
alert('失败:' + oAjax.status);
}
}
};
};
};
</script>
</head>
<body>
<input id="btn1" type="button" value="读取" />
<div id='div1'></div>
</body>
</html>
image.png