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 XML实现两级级联下拉列表
javascript显示选择目录对话框的代码
javascript HTML操作代码
用js删除tbody的代码
javascript firefox不显示本地预览图片问题的解决方法
js Array的用法总结
js fromCharCode输出26个字母的代码
js option删除代码集合
JavaScript面向对象之体会[总结]
javascript 命名空间以提高代码重用性
javascript vvorld 在线加密破解方法
javascript 限制输入和粘贴(IE和火狐3.x下测试通过)
火狐浏览器(firefox)下获得Event对象以及keyCode
刷新页面实现方式总结(HTML,ASP,JS)
Ajax,UTF-8还是GB2312 eval 还是execScript
javascript 出生日期和身份证判断大全
JS清空上传控件input(type="file")的值的代码
javascript 限制输入和粘贴(IE,firefox测试通过)
js实现简单模态窗口,背景灰显
option挡住div解决方法

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: 429 ::
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