图片放大镜效果，供大家参考，具体内容如下
一难点：不让黄盒子出界
二难点：让大盒子相应移动（比例）
<html lang="en">
<head>
<meta charset="UTF-8">
<title>我的放大镜</title>
<style>
*{
margin: 0;
padding: 0;
}
.box{
margin: 100px;
position: relative;
}
.small{
width: 350px;
height: 350px;
border: 1px solid #999;
position: relative;
}
.select{
display: none;
width: 100px;
height: 100px;
background: rgba(255,255,0,0.4);
position: absolute;
left: 0;
top: 0;
cursor: move;
}
.big{
display: none;
position: absolute;
left: 360px;
top: 0;
width: 450px;
height: 450px;
border: 1px solid #ccc;
overflow: hidden;
}
.big img{
position: absolute;
left: 0;
top: 0;
}
</style>
</head>
<body>
<div class="box">
<div class="small" id="smallbox">
<img src="images/001.jpg" alt="">
<div class="select" id="mask" style="display:none;"></div>
</div>
<div class="big" id="bigbox">
<img src="images/0001.jpg" alt="">
</div>
</div>
<script>
var smallbox = document.getElementById('smallbox');
var bigbox = document.getElementById('bigbox');
var mask = document.getElementById('mask');
var bigImg = bigbox.children[0];
smallbox.onmouseover = function(){
mask.style.display = "block";
bigbox.style.display = "block";
}
smallbox.onmouseout = function(){
mask.style.display = "none";
bigbox.style.display = "none";
}
smallbox.onmousemove = function(event){
var event = event || window.event;
var x = event.clientX - this.offsetParent.offsetLeft - mask.offsetWidth/2;
var y = event.clientY - this.offsetParent.offsetTop - mask.offsetHeight/2;
//不让黄盒子出界
if(x < 0){
x = 0;
}else if(x > smallbox.offsetWidth - mask.offsetWidth){
x = smallbox.offsetWidth - mask.offsetWidth;
}
if(y<0) {
y = 0;
}else if(y > smallbox.offsetHeight - mask.offsetHeight){
y = smallbox.offsetHeight - mask.offsetHeight;
}
mask.style.left = x + "px";
mask.style.top = y + "px";
bigImg.style.left = -x/smallbox.offsetWidth * bigbox.offsetWidth + "px"; //注意是-x
bigImg.style.top = -y/smallbox.offsetHeight * bigbox.offsetHeight + "px";
}
</script>
</body>
</html>
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。
