JS+CSS实现一个气泡提示框

分享一个气泡提示框，练习的技术有：（1）JS响应鼠标的事件；（2）纯CSS制作三角形。

效果这样：
 
这是html：


代码如下:

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>气泡对话框</title>
<script src="myBubbleTooltip.js"></script>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.0/jquery.min.js"></script>
<style type="text/css">
h1{
font-size: 60px;
margin-top: 0;
font-family: Arial, sans-serif;
text-shadow: 2px 0px 10px #292929;
letter-spacing: 0px;
text-decoration: none;
color: #DDDDDD;
}
div#left{
border: 1px solid #CCCCCC;
width: 200px;
height: 300px;
background-color: #EEEEEE;
float: left;
margin: 0 0 0 20px;
}
div#content{
border: 1px solid #CCCCCC;
width: 600px;
height: 300px;
background-color: #EEEEEE;
float: left;
margin: 0px 20px;
}
div#editor{
border: 1px solid #CCCCCC;
float: left;
width: 300px;
height: 300px;
}
div#test{
border: 2px solid #cccccc;
width: 400px;
height: 400px;
}
.bubble_tooltip_common{
z-index: 1;
color:#333333;
width:150px;
position:absolute;
display:none;
border: 1px solid #AAAAAA;
box-shadow: 0px 0px 10px #AAAAAA;
border-radius: 5px;
padding: 5px 10px;
background-color: #FEFAB8;
}

代码如下:

/*尖端指向左侧的三角形，外缘*/
.triRight{
z-index: 2;
border: 10px solid #AAAAAA;
border-color: transparent #AAAAAA transparent transparent;
width: 0;
height: 0;
position: absolute;
left:-20px;
top: 5px;
}

代码如下:

<PRE class=html name="code">/*尖端指向左侧的三角形，内部，*/</PRE>.triRightInner{ z-index: 3; border: 8px solid #FEFAB8; border-color: transparent #FEFAB8 transparent transparent;<SPAN style="FONT-FAMILY: Arial, Helvetica, sans-serif">/*颜色应与提示框的background-color一致*/</SPAN><BR>
width: 0; height: 0; position: absolute; left:-16px; top:7px;}</style></head><body> <div class="bubble_tooltip_common" id="bubble_tooltip"> <label class="triRight"></label> <label class="triRightInner"></label> <span id="bubble_tooltip_content"></span> </div>
<h1>气泡对话框</h1> <div id="left"> <p> <span onmouseover="showToolTip(event,'这是一个提示框。')" onmouseout="hideToolTip()">鼠标放于此处，会弹出一个气泡对话框。</span></p> </div> <div id="content"> <p><a href="#" onmouseover="showToolTip(event,'This is the content of the tooltip.')" onmouseout="hideToolTip()">sharejs.com</a></p>
</div> <div id="editor" contenteditable> [Click to edit.] </div></body></html>
<PRE></PRE>
<P></P>
<P><SPAN style="FONT-FAMILY: Microsoft YaHei; FONT-SIZE: 18px"><STRONG>这是JavaScript代码：</STRONG></SPAN></P>
<P></P>
<PRE class=javascript name="code">function showToolTip(e,text){
if(document.all)e = event;
var obj = document.getElementById('bubble_tooltip');
var obj2 = document.getElementById('bubble_tooltip_content');
obj2.innerHTML = text;
var st = Math.max(document.body.scrollTop,document.documentElement.scrollTop);
if(navigator.userAgent.toLowerCase().indexOf('safari')>=0)st=0;
var leftPos = e.clientX + 20; //clientX 事件属性返回当事件被触发时鼠标指针相对于浏览器页面（或客户区）的水平坐标
if(leftPos<0)leftPos = 0;
obj.style.left = leftPos + 'px';
obj.style.top = e.clientY + st + 'px';
obj.style.display = 'block';
fadeIn(obj,5,100);
}

function hideToolTip()
{
var obj = document.getElementById('bubble_tooltip');
//obj.style.display = 'none';
fadeOut(obj,5,0);
}

//设置元素透明度,透明度值按IE规则计,即0~100
function SetOpacity(ev, v){
ev.filters ? ev.style.filter = 'alpha(opacity=' + v + ')' : ev.style.opacity = v / 100;
}

//淡入效果(含淡入到指定透明度)
function fadeIn(elem, speed, opacity){
/*
* 参数说明
* elem==>需要淡入的元素
* speed==>淡入速度,正整数(可选)
* opacity==>淡入到指定的透明度,0~100(可选)
*/
speed = speed || 20;
opacity = opacity || 100;
//显示元素,并将元素值为0透明度(不可见)
elem.style.display = 'block';
SetOpacity(elem, 0);
//初始化透明度变化值为0
var val = 0;
//循环将透明值以2递增,即淡入效果
(function(){
SetOpacity(elem, val);
val += 5;
if (val <= opacity) {
setTimeout(arguments.callee, speed)
}
})();
}

//淡出效果(含淡出到指定透明度)
function fadeOut(elem, speed, opacity){
/*
* 参数说明
* elem==>需要淡入的元素
* speed==>淡入速度,正整数(可选)
* opacity==>淡入到指定的透明度,0~100(可选)
*/
speed = speed || 20;
opacity = opacity || 0;
//初始化透明度变化值为0
var val = 100;
//循环将透明值以5递减,即淡出效果
(function(){
SetOpacity(elem, val);
val -= 5;
if (val >= opacity) {
setTimeout(arguments.callee, speed);
}else if (val < 0) {
//元素透明度为0后隐藏元素
elem.style.display = 'none';
}
})();
}</PRE><BR>
<BR>
<P></P>
<PRE></PRE>