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：
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<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<meta name="developer" content="Realazy" />
<title>Bubble in JavaScript DOM</title>
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all[i].onmouseover = function(e){
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log.value = '鼠标现在进入的是： ' + this.nodeName;
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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;
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<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.qb5200.com/#"><span>Bubbllllllllllllllle</span></a>
</li>
<li>
<a href="//www.qb5200.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.qb5200.com/#"><span>Bubbllllllllllllllle</span></a>
</li>
<li>
<a href="//www.qb5200.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>
希望本文所述对大家JavaScript程序设计有所帮助。
