当前位置: 首页 > 图文教程 > 网络编程 > Javascript > Javascript 的addEventListener()及attachEvent()区别分析

Javascript
JavaScript如何重构嵌套循环和递归
JS应用在Firebug中的扩展架构模式
提升JS性能:将递归转换为迭代
IE7浏览器下缩放图片失真问题
JavaScript对DOM进行操作的指导性原则
JavaScript有趣实例:胸罩罩杯尺寸计算器
Firefox的Firebug扩展:FireScope
Mozilla的JavaScript引擎__noSuchMethod__()方法
JavaScript+CSS制作的网站导航菜单
javascript的私有成员(private)
Javascript绘制分析曲线图
ie6使用js支持hover伪类
收集的25个下拉网页菜单特效Javascript脚本
Javascript框架的自定义事件
总结Javascript调用函数的方法
JS教程:call、apply、callee用法
JS教程:数组类型检测和集合检测
兼容FF的设为首页与收藏网站的JS代码
Javascript教程:PopUp对象
JS读写Cookie以及设置过期时间

Javascript 的addEventListener()及attachEvent()区别分析


出处:互联网   整理: 软晨网(RuanChen.com)   发布: 2009-09-12   浏览: 390 ::
收藏到网摘: n/a

大家都知道事件的用法就是当某个事件(状况)被触发了之后就会去执行某个Function, 尤其是Javascript, 在当红AJAX的催化下, 了解Javascript的Event用法更加重要, 在这里就大概介绍一下avascript的Event用法.

从W3C的发展时间轴来看, DOM(Document Object Model)的模型可以分为两种, DOM 0 及 DOM 2. 从数字来看就可以知道DOM 0 当然是比较旧的协议, 我们可以从以下的表格来看:

DOM1 协定:

Event Name

Description

onblur()

The element has lost focus (that is, it is not selected by the user).

onchange0

The element has either changed (such as by typing into a text field) or the element has lost focus.

onclick0

The mouse has been clicked on an element.

ondblclick()

The mouse has been double-clicked on an element.

onfocus()

The element has gotten focus.

onkeydown()

A keyboard key has been pressed down (as opposed to released) while the element has focus.

onkeypress()

A keyboard key has been pressed while the element has focus.

onkeyup()

A keyboard key has been released while the element has focus.

onload()

The element has loaded (document, frameset, or image).

onmousedown()

A mouse button has been pressed.

onmousemove()

The mouse has been moved.

onmouseout()

The mouse has been moved off of or away from an element.

onmouseover()

The mouse has moved over an element.

onmouseup()

A mouse button has been released.

onreset()

The form element has been reset, such as when a form reset button is pressed.

onresize()

The window's size has been changed.

onselect()

The text of a form element has been selected.

onsubmit()

The form has been submitted.

onunload()

The document or frameset has been unloaded.


DOM2 的进化:

DOM 0 Event

DOM 2 Event

onblur()

blur

onfocus()

focus

onchange()

change

onmouseover()

mouseover

onmouseout()

mouseout

onmousemove()

mousemove

onmousedown()

mousedown

onmouseup()

mouseup

onclick()

click

ondblclick()

dblclick

onkeydown()

keydown

onkeyup()

keyup

onkeypress()

keypress

onsubmit()

submit

onload()

load

onunload()

unload

新的DOM2 用法可以addEventListener()这个函数来观察到:

addEventListener(event,function,capture/bubble);

参数event如上表所示, function是要执行的函数, capture与bubble分别是W3C制定得两种时间模式,简单来说capture就是从document的开始读到最后一行, 再执行事件, 而bubble则是先寻找指定的位置再执行事件.
capture/bubble的参数是布尔值, True表示用capture, False则是bubble.Windows Internet Explorer也有制定一种EventHandler, 是 attachEvent(), 格式如下:

window.attachEvent(”submit”,myFunction());

比较特别的是attachEvent不需要指定capture/bubble的参数, 因为在windows IE环境下都是使用Bubble的模式.这里用图像的Rollover例子来表现事件的用法:

<!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01//EN”
http://www.w3.org/TR/html4/strict.dtd“>
<html>
<head>
<title>Rollover</title>
<script type=”text/javascript”>function moveOver(imgObj) {
if (typeof window.addEventListener != “undefined”) {
imgObj.addEventListener(”mouseover”,function(){imgObj.src = imgObj.id +
“_over.png”;}, false);
imgObj.addEventListener(”mouseout”, function(){imgObj.src = imgObj.id +
“_default.png”;}, false);
} else {
imgObj.attachEvent(”onmouseover”,function(){imgObj.src = imgObj.id +
“_over.png”;});
imgObj.attachEvent(”onmouseout”, function(){imgObj.src = imgObj.id +
“_default.png”;});
}
}

function rollover() {
var images = document.getElementsByTagName(”img”);
var roll = new RegExp (”rollover”);
var preload = [];
for (var i = 0; i < images.length; i++) {
if (images[i].id.match(roll)) {
preload[i] = new Image();
preload[i].src = images[i].id + “_over.png”;

moveOver(images[i]);
}
}
}
if (typeof window.addEventListener != “undefined”) {
window.addEventListener(”load”,rollover,false);
} else {
window.attachEvent(”onload”,rollover)
}
</script>
</head>
<body>
<p><img id=”rollover_home” name=”img_home” src=”rollover_home_default.png”
alt=”Home”></p>
<p><img id=”rollover_about” name=”img_about” src=”rollover_about_default.png”
alt=”About”></p>
<p><img id=”rollover_blog” name=”img_blog” src=”rollover_blog_default.png”
alt=”Blog”></p>
<p><img id=”logo” name=”img_logo” src=”logo.png” alt=”Braingia Logo”></p>
</body>
</html>

上述的 typeof window.addEventListener != “undefined” 程序代码可以判断使用者的浏览器是否支持AddEventListener这个事件模型, 如果不支持就使用attachEvent.

W3C 及 IE 同时支持移除指定的事件, 用途是移除设定的事件, 格式分别如下:

W3C格式:

removeEventListener(event,function,capture/bubble);

Windows IE的格式如下:

detachEvent(event,function);

数据参考: Chapter 14 - Browsers and JavaScript, JavaScript Step by Step, by Steve Suehring