<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>
<style>
.img {
width: 300px;
height: 400px;
position: relative;
}
.img img {
width: 100%;
height: 100%;
}
.mask {
width: 200px;
height: 200px;
position: absolute;
left: 0;
top: 0;
background-color: yellow;
opacity: 0.3;
display: none;
cursor: move;
}
.big {
width: 400px;
height: 400px;
position: absolute;
left: 300px;
top: 0;
overflow: hidden;
display: none;
}
.big img {
width: 150%;
height: 200%;
position: absolute;
left: 0;
top: 0;
}
</style>
<title>Document</title>
</head>
<body>
<div class="img">
<img src="./8131572850838_.pic.jpg" alt="">
<div class="mask"></div>
<div class="big">
<img src="./8131572850838_.pic.jpg" alt="">
</div>
</div>
<script>
$(function () {
var imgBox = $('.img')
var mask = $('.mask')
var big = $('.big')
imgBox.on({
mouseover: function (e) {
mask.css({ 'display': 'block' })
big.css({ 'display': 'block' })
},
mouseout: function (e) {
mask.css({ 'display': 'none' })
big.css({ 'display': 'none' })
},
mousemove: function (e) {
// 鼠标在盒子中的位置
var x = e.pageX - imgBox.offset().left
var y = e.pageY - imgBox.offset().top
// 遮挡层的坐标
var maskX = x - mask.width() / 2
var maskY = y - mask.height() / 2
// 遮挡层最大移动距离
var maxX = imgBox.width() - mask.width()
var maxY = imgBox.height() - mask.height()
if (maskX <= 0) {
maskX = 0
} else if (maskX > maxX) {
maskX = maxX
}
if (maskY <= 0) {
maskY = 0
} else if (maskY > maxY) {
maskY = maxY
}
mask.css({
'left': maskX,
'top': maskY
})
// 大图片的最大移动距离
var bigImg = big.children('img')
var bigMaxX = bigImg.width() - big.width()
var bigMaxY = bigImg.height() - big.height()
// 大图片移动距离
// mask最小移动距离 / mask最大移动距离 = big最小移动距离 / big最大移动距离
var bigX = maskX * bigMaxX / maxX
var bigY = maskY * bigMaxY / maxY
// 相反方向移动需要 负号
bigImg.css({
'left': -bigX,
'top': - bigY
})
}
}) // imgBox.on
})
</script>
</body>
</html>