JS实现放大镜效果，供大家参考，具体内容如下
鼠标移到图片上就可以放大一块区域
代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
#small{
width: 700px;
height: 340px;
position: absolute;
left: 70px;
top: 100px;
}
#small img{
width: 100%;
height: 100%;
}
#mark{
width: 200px;
height: 200px;
background-color:white;
position: absolute;
opacity: 0.5;
filter: alpha(opacity=50);
left: 0px;
top: 0px;
display: none;
}
#big{
width: 400px;
height: 400px;
border: 1px solid black;
left: 800px;
top: 100px;
position: absolute;
overflow: hidden;
display: none;
}
#big img{
width: 1400px;
height: 680px;
position: absolute;
left: 0px;
top: 0px;
}
</style>
<script>
window.onload = function(){
var oSmall = document.getElementById("small");
var oBig = document.getElementById("big");
var oMark = document.getElementById("mark");
var oBigImg = oBig.getElementsByTagName("img")[0];
oSmall.onmouseover = function(){
oMark.style.display = "block";
oBig.style.display = "block";
}
oSmall.onmouseout = function(){
oMark.style.display = "none";
oBig.style.display = "none";
}
oSmall.onmousemove = function(ev){
var e = ev || window.event;
var l = e.clientX - oSmall.offsetLeft - 100;
if(l <= 0){
l = 0;
}
if(l >= (700-200)){
l = 500;
}
var t = e.clientY - oSmall.offsetTop - 100;
if(t <= 0){
t = 0;
}
if(t >= (340-200)){
t = 140;
}
oMark.style.left = l + 'px';
oMark.style.top = t + 'px';
/* 右边图片移动方向与左边图片方向相反且成倍数移动 */
oBigImg.style.left = l * -2 + 'px';
oBigImg.style.top = t * -2 + 'px';
}
}
</script>
</head>
<body>
<div id="small">
<img src="/UploadFiles/2021-04-02/地狱之门卫士 加里奥.jpg">
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。