时间:2021-07-01 10:21:17 帮助过:7人阅读
本文实例讲述了javascript事件冒泡的定义与用法。分享给大家供大家参考,具体如下:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="zh" xml:lang="zh">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<meta name="developer" content="Realazy" />
<title>Bubble in JavaScript DOM</title>
<style type="text/css" media="screen">
div * {
display: block;
margin: 4px;
padding: 4px;
border: 1px solid white;
}
textarea {
width: 20em;
height: 2em;
}
</style>
<script type="text/javascript">
//<![CDATA[
function init(){
var log = document.getElementsByTagName('textarea')[0];
var all = document.getElementsByTagName('div')[0].getElementsByTagName('*');
for (var i = 0, n = all.length; i < n; ++i) {
all[i].onmouseover = function(e){
this.style.border = '1px solid red';
log.value = '鼠标现在进入的是: ' + this.nodeName;
};
all[i].onmouseout = function(e){
this.style.border = '1px solid white';
};
}
var all2 = document.getElementsByTagName('div')[1].getElementsByTagName('*');
for (var i = 0, n = all2.length; i < n; ++i) {
all2[i].onmouseover = function(e){
this.style.border = '1px solid red';
if (e) //停止事件冒泡
e.stopPropagation();
else
window.event.cancelBubble = true;
log.value = '鼠标现在进入的是: ' + this.nodeName;
};
all2[i].onmouseout = function(e){
this.style.border = '1px solid white';
};
}
}
window.onload = init;
//]]>
</script>
</head>
<body>
<h1>Bubble in JavaScript DOM</h1>
<p>
DOM树的结构是:
</p>
<pre><code>
UL
- LI
- A
- SPAN
</code></pre>
<div>
<ul>
<li>
<a href="//www.gxlcms.com/#"><span>Bubbllllllllllllllle</span></a>
</li>
<li>
<a href="//www.gxlcms.com/#"><span>Bubbllllllllllllllle</span></a>
</li>
</ul>
</div>
<textarea>
</textarea>
<p>
鼠标进入UL的任何一个子元素,如果不停止冒泡,我们从UL到SPAN都定义了鼠标悬停(
<code>
mouseover
</code>)事件,这个事件会上升了UL,从而从鼠标所进入的元素到UL元素都会有红色的边。
</p>
<div>
<ul>
<li>
<a href="//www.gxlcms.com/#"><span>Bubbllllllllllllllle</span></a>
</li>
<li>
<a href="//www.gxlcms.com/#"><span>Bubbllllllllllllllle</span></a>
</li>
</ul>
</div>
<p>
如果停止冒泡,事件不会上升,我们就可以获取精确的鼠标进入元素。
</p>
</body>
</html>
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希望本文所述对大家JavaScript程序设计有所帮助。