<!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>
#box1 {
width: 300px;
height: 300px;
border: 1px solid black;
position: absolute;
left: 30px;
top: 30px;
}
#box1 img {
width: 100%;
height: 100%;
}
#box2 {
display: none;
width: 300px;
height: 300px;
border: 1px solid white;
position: absolute;
left: 500px;
top: 30px;
overflow: hidden;
}
#box2 img {
width: 600px;
height: 600px;
position: absolute;
top: 0;
left: 0;
}
#mengceng {
display: none;
width: 70px;
height: 70px;
background-color: black;
position: absolute;
top: 0;
left: 0;
opacity: 0.5;
}
</style>
<script>
window.onload = function () {
var BOX1 = document.getElementById("box1");
var BOX2 = document.getElementById("box2");
var Mengceng = document.getElementById("mengceng");
var IMG = BOX2.getElementsByTagName("img")[0];
BOX1.onmouseover = function () {
Mengceng.style.display = "block";
BOX2.style.display = "block";
}
BOX1.onmouseout = function () {
Mengceng.style.display = "none";
BOX2.style.display = "none";
}
BOX1.onmousemove = function(ev){
var e = ev || window.event;
var l = e.clientX - 60;
var t = e.clientY - 60;
Mengceng.style.left = l+ "px";
Mengceng.style.top = t + "px";
IMG.style.left = l * -2 + "px";
IMG.style.top = t * -2 + "px";
if(l <= 0){
l = 0;
}
if(l >= 230){
l = 230;
}
if(t <= 0){
t = 0;
}
if(t >= 230){
t = 230;
}
}
}
</script>
</head>
<body>
<div id="box1">
<img src="../图片的使用/放大镜图片.jfif" alt="">
<div id="mengceng"></div>
</div>
<div id="box2">
<img src="../图片的使用/放大镜图片.jfif" alt="">
</div>
</body>
</html>
我把
if(l <= 0){
l = 0;
}
if(l >= 230){
l = 230;
}
if(t <= 0){
t = 0;
}
if(t >= 230){
t = 230;
}
代码放到
var e = ev || window.event;
var l = e.clientX - 60;
var t = e.clientY - 60;
Mengceng.style.left = l+ "px";
Mengceng.style.top = t + "px";
IMG.style.left = l * -2 + "px";
IMG.style.top = t * -2 + "px";
下面后，if的代码就不能正常执行了，这是为什么?函数的调用里面的代码不是不分顺序的吗？
