原生js实现的放大镜效果-js教程-PHP中文网

原生js实现的放大镜效果

高洛峰

发布： 2016-10-15 09:32:50

原创

1267人浏览过

这是我用原生js写的放大镜效果，与各种各样的框架技术相比，我喜欢使用原生的js，在这里，想和大家一起谈谈原生和框架技术的理解与个人喜好。

<!DOCTYPE HTML>
<html>
<head>
<title>js放大镜效果</title>
<meta http-equiv="content-type" content="text/html;charset=utf-8"/>
<style>
*{
margin:0px;
padding:0px;
border:none;
list-style:none;
}
#box{
margin:80px auto;
width: 352px;
}
#box p
{
width: 350px;
height: 350px;
border: 1px solid #ddd;
margin-bottom: 5px; 
}
#box p img
{
width:350px;
height:350px;
}
#box h1
{
width: 352px;
height: 54px;
overflow:hidden; 
position:relative;
}
#box h1 div
{
width:310px;
height: 54px;
margin:0px auto;
position:relative;
}
#box h1 div ul
{
position:absolute;
left: 0px;
top: 0px;
}
#box h1 ul li
{
width: 62px; 
float: left;
}
#box h1 ul li img
{
width: 50px;
height: 50px;
padding: 1px;
border: 1px solid #CECFCE;
}
#box h1 img.hoveredThumb{
border: 2px solid #e4393c;
padding: 0;
}
/*中等大小的图片显示区域*/
p#medImgBox{
position: relative;
}
#jing{
position: absolute;
left: 0;
top: 0;
width: 175px;
height: 175px;
border-radius:50%;
background: #ffd;
opacity: 0.7;
display: none;
}
/*悬于图片/jing上方的专用于接收鼠标移动事件的
一个完全透明的层*/
#medImgBox #mian{
display: block;
position: absolute;
width: 100%;
height: 100%;
top: 0;
left: 0;
cursor: move;
opacity: 0;
}
/**
大图显示区域
**/
#largeImgBox{
position:absolute;
width: 175px;
height: 175px;
border-radius:50%;
border: 1px solid #faa;
top: 0px;
left: 352px;	
overflow: hidden;
display: none;
}
#largeImg{
display: none;
position: absolute;
}
</style>	
</head>
<body >
<div id="box">
<p id="medImgBox">
@@##@@
<span id="jing"></span>
<span id="mian"></span>
<span id="largeImgBox">
@@##@@
</span>
</p>
<h1>
<div>
<ul id="list">
<li>@@##@@</li>
<li>@@##@@</li>
<li>@@##@@</li>
<li>@@##@@</li>
<li>@@##@@</li>
</ul>
</div>
</h1>
</div>

<script>
var imgList = document.querySelectorAll('#box ul li img');
for(var i=0; i@@##@@(w*2-w/2)){
left = w*2 - w;
}
if(y>(h*2-h/2)){
top = h*2 - h;
}
jing.style.left = left+'px';
jing.style.top = top+'px';
//修改大图的位置/
var largeImg = document.getElementById('largeImg');
largeImg.style.left = (-left*largeImg.width/350) + 'px';
largeImg.style.top = (-top*largeImg.height/350)+'px';
}
document.querySelector('#mian').onmouseover = function(){
//显示jing
var jing = document.getElementById('jing');
jing.style.display = 'block';
var largeImgBox = document.getElementById('largeImgBox');
largeImgBox.style.display = 'block';
//获取当前要显示的大图的src
var src = document.querySelector('#mediumImg').src;
var dotIndex = src.lastIndexOf('.');
var prefix = src.substring(0, dotIndex-2);
var suffix = src.substring(dotIndex);
src = prefix + '-l'+ suffix;
var largeImg = document.getElementById('largeImg');
largeImg.src = src;
largeImg.style.display='block';
}
document.querySelector('#mian').onmouseout = 
function(){
//除去jing
var jing = document.getElementById('jing');
jing.style.display = 'none';
//除去大图显示区
document.getElementById('largeImgBox').style.display = 'none';
}
</script>
</body>
</html>

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