js实现图片放大镜功能，简单明了

请添加图片描述
写购物项目的时候，需要放大图片，这里用js写了一个方法，鼠标悬浮的时候放大当前图片

这个是class写法

<!--* @Descripttion: * @Author: 苍狼一啸八荒惊* @LastEditTime: 2024-07-10 09:41:34* @LastEditors: 夜空苍狼啸
--><!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>商品详情</title><!-- <link rel="stylesheet" href="./css/detail.css"> --><style>.product_wrapper {width: 1200px;margin: 0 auto;font: 12px "Hiragino Sans GB", "Verdana", "Simsun";background-color: #fff;}.product_wrapper .detail {overflow: hidden;}.product_wrapper .detail .list_detail {width: 320px;height: 320px;float: left;padding: 0 20px 30px 0;position: relative;}.product_wrapper .detail .list_detail .list_detail_1 {width: 280px;height: 280px;position: relative;}.product_wrapper .detail .list_detail .list_detail_1>img {width: 100%;height: 100%;}.product_wrapper .detail .list_detail .list_detail_1 .mask {width: 150px;height: 150px;background: url(../img/zoom_pup.png);opacity: 0.5;position: absolute;left: 30px;top: 40px;pointer-events: none;display: none;}.product_wrapper .detail .list_detail .list_detail_2 {position: absolute;left: 0;bottom: 0;display: flex;justify-content: space-evenly;align-items: center;}.product_wrapper .detail .list_detail .list_detail_2>img {width: 54px;height: 54px;margin-right: 50px;cursor: pointer;}.product_wrapper .detail .list_detail .list_detail_2 .active {box-shadow: 0 0 8px rgb(255, 255, 255) inset, 0 0 8px red;}.product_wrapper .detail .list_detail .list_detail_enlarge {width: 480px;height: 480px;position: absolute;position: absolute;left: 90%;top: 0;overflow: hidden;display: none;z-index: 999;}.product_wrapper .detail .list_detail .list_detail_enlarge>img {display: block;width: 800px;height: 800px;position: absolute;left: 0;top: 0;}</style>
</head><body><div class="product_wrapper"><div class="detail hover"><div class="list_detail" id="box"><!-- 放大镜 --><div class="list_detail_1"><img src="./img/lx1.jpg" alt=""><div class="mask"></div></div><div class="list_detail_2"><img src="./img/lx1.jpg" class="active" alt="" data-show="./img/lx1.jpg" data-bg="./img/lx1.jpg"><img src="./img/lx2.jpg" alt="" data-show="./img/lx2.jpg" data-bg="./img/lx2.jpg"><img src="./img/lx3.jpg" alt="" data-show="./img/lx3.jpg" data-bg="./img/lx3.jpg"></div><div class="list_detail_enlarge enlarge"><!-- <img src="./img/lx1.jpg" alt=""> --><img src="http://img3m2.ddimg.cn/27/17/25583112-1_u_11.jpg" alt=""></div></div></div></div><!-- 引入放大镜 --><!-- <script src="./js/detail.js"></script> --><script>// 放大镜class Enlarge {constructor(select) {// 0-1. 获取到范围元素, 目的是为了让所有内容都出现在这里面this.ele = document.querySelector(select)this.show = this.ele.querySelector('.list_detail_1')this.mask = this.ele.querySelector('.mask')this.list = this.ele.querySelector('.list_detail_2')this.enlarge = this.ele.querySelector('.enlarge')this.bg = this.enlarge.firstElementChild// 需要一些尺寸数据this.show_w = this.show.clientWidththis.show_h = this.show.clientHeight// 非行内样式获取this.mask_w = parseInt(window.getComputedStyle(this.mask).width)this.mask_h = parseInt(window.getComputedStyle(this.mask).height)this.bg_w = parseInt(window.getComputedStyle(this.bg).width)this.bg_h = parseInt(window.getComputedStyle(this.bg).height)// 在这里调用函数来启动this.setScale()this.overOut()this.listChange()this.move()}// 计算数值setScale() {// 1. 计算数值this.enlarge_w = this.mask_w * this.bg_w / this.show_wthis.enlarge_h = this.mask_h * this.bg_h / this.show_h// 2. 给 this.enlarge 赋值this.enlarge.style.width = this.enlarge_w + 'px'this.enlarge.style.height = this.enlarge_h + 'px'}// 鼠标经过显示遮罩层, 图片放大overOut() {this.show.addEventListener('mouseover', () => {this.mask.style.display = 'block'this.enlarge.style.display = 'block'})this.show.addEventListener('mouseout', () => {this.mask.style.display = 'none'this.enlarge.style.display = 'none'})}// tab 切换listChange() {this.list.addEventListener('click', e => {// 处理事件对象兼容e = e || window.event// 处理事件目标兼容const target = e.target || e.srcElement// 判断点击的是 img 标签if (target.nodeName !== 'IMG') return// 1. 切换 img 类名for (let i = 0; i < this.list.children.length; i++) {this.list.children[i].classList.remove('active')}target.classList.add('active')// 2. 切换 show里面img 和 bg 的 srcconst showUrl = target.dataset.showconst bgUrl = target.dataset.bgthis.show.firstElementChild.src = showUrlthis.bg.src = bgUrl})}// 鼠标移动move() {// 1. 绑定事件this.show.addEventListener('mousemove', e => {e = e || window.event// 2. 获取光标坐标点let x = e.offsetX - this.mask_w / 2let y = e.offsetY - this.mask_h / 2// 3. 边界值判断if (x <= 0) x = 0if (y <= 0) y = 0if (x >= this.show_w - this.mask_w) x = this.show_w - this.mask_wif (y >= this.show_h - this.mask_h) y = this.show_h - this.mask_hthis.mask.style.left = x + 'px'this.mask.style.top = y + 'px'const bg_x = x * this.enlarge_w / this.mask_w * -1const bg_y = y * this.enlarge_h / this.mask_h * -1this.bg.style.left = bg_x + 'px'this.bg.style.top = bg_y + 'px'})}}const enlarge = new Enlarge('#box')</script></body></html>

这个是函数写法

<!--* @Descripttion: * @Author: 苍狼一啸八荒惊* @LastEditTime: 2024-07-10 09:41:34* @LastEditors: 夜空苍狼啸
--><!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>商品详情</title><!-- <link rel="stylesheet" href="./css/detail.css"> --><style>.product_wrapper {width: 1200px;margin: 0 auto;font: 12px "Hiragino Sans GB", "Verdana", "Simsun";background-color: #fff;}.product_wrapper .detail {overflow: hidden;}.product_wrapper .detail .list_detail {width: 320px;height: 320px;float: left;padding: 0 20px 30px 0;position: relative;}.product_wrapper .detail .list_detail .list_detail_1 {width: 280px;height: 280px;position: relative;}.product_wrapper .detail .list_detail .list_detail_1>img {width: 100%;height: 100%;}.product_wrapper .detail .list_detail .list_detail_1 .mask {width: 150px;height: 150px;background: url(../img/zoom_pup.png);opacity: 0.5;position: absolute;left: 30px;top: 40px;pointer-events: none;display: none;}.product_wrapper .detail .list_detail .list_detail_2 {position: absolute;left: 0;bottom: 0;display: flex;justify-content: space-evenly;align-items: center;}.product_wrapper .detail .list_detail .list_detail_2>img {width: 54px;height: 54px;margin-right: 50px;cursor: pointer;}.product_wrapper .detail .list_detail .list_detail_2 .active {box-shadow: 0 0 8px rgb(255, 255, 255) inset, 0 0 8px red;}.product_wrapper .detail .list_detail .list_detail_enlarge {width: 480px;height: 480px;position: absolute;position: absolute;left: 90%;top: 0;overflow: hidden;display: none;z-index: 999;}.product_wrapper .detail .list_detail .list_detail_enlarge>img {display: block;width: 800px;height: 800px;position: absolute;left: 0;top: 0;}</style>
</head><body><div class="product_wrapper"><div class="detail hover"><div class="list_detail" id="box"><!-- 放大镜 --><div class="list_detail_1"><img src="./img/lx1.jpg" alt=""><div class="mask"></div></div><div class="list_detail_2"><img src="./img/lx1.jpg" class="active" alt="" data-show="./img/lx1.jpg" data-bg="./img/lx1.jpg"><img src="./img/lx2.jpg" alt="" data-show="./img/lx2.jpg" data-bg="./img/lx2.jpg"><img src="./img/lx3.jpg" alt="" data-show="./img/lx3.jpg" data-bg="./img/lx3.jpg"></div><div class="list_detail_enlarge enlarge"><img src="./img/lx1.jpg" alt=""></div></div></div></div><!-- 引入放大镜 --><!-- <script src="./js/detail.js"></script> --><script>/** @Descripttion: * @Author: 苍狼一啸八荒惊* @LastEditTime: 2024-07-10 10:18:57* @LastEditors: 夜空苍狼啸*/// 放大镜// 0-1. 获取到范围元素, 目的是为了让所有内容都出现在这里面
let ele = document.querySelector('#box')
let show = ele.querySelector('.list_detail_1')
let mask = ele.querySelector('.mask')
let list = ele.querySelector('.list_detail_2')
let enlarge = ele.querySelector('.enlarge')
let bg = enlarge.firstElementChild
// 需要一些尺寸数据
let show_w = show.clientWidth
let show_h = show.clientHeight
// 非行内样式获取
let mask_w = parseInt(window.getComputedStyle(mask).width)
let mask_h = parseInt(window.getComputedStyle(mask).height)
let bg_w = parseInt(window.getComputedStyle(bg).width)
let bg_h = parseInt(window.getComputedStyle(bg).height)// 计算数值
// 1. 计算数值
enlarge_w = mask_w * bg_w / show_w
enlarge_h = mask_h * bg_h / show_h// 2. 给 enlarge 赋值
enlarge.style.width = enlarge_w + 'px'
enlarge.style.height = enlarge_h + 'px'// 鼠标经过显示遮罩层, 图片放大show.addEventListener('mouseover', () => {mask.style.display = 'block'enlarge.style.display = 'block'
})show.addEventListener('mouseout', () => {mask.style.display = 'none'enlarge.style.display = 'none'
})// tab 切换list.addEventListener('click', e => {// 处理事件对象兼容e = e || window.event// 处理事件目标兼容const target = e.target || e.srcElement// 判断点击的是 img 标签if (target.nodeName !== 'IMG') return// 1. 切换 img 类名for (let i = 0; i < list.children.length; i++) {list.children[i].classList.remove('active')}target.classList.add('active')// 2. 切换 show里面img 和 bg 的 srcconst showUrl = target.dataset.showconst bgUrl = target.dataset.bgshow.firstElementChild.src = showUrlbg.src = bgUrl
})// 鼠标移动// 1. 绑定事件
show.addEventListener('mousemove', e => {e = e || window.event// 2. 获取光标坐标点let x = e.offsetX - mask_w / 2let y = e.offsetY - mask_h / 2// 3. 边界值判断if (x <= 0) x = 0if (y <= 0) y = 0if (x >= show_w - mask_w) x = show_w - mask_wif (y >= show_h - mask_h) y = show_h - mask_hmask.style.left = x + 'px'mask.style.top = y + 'px'const bg_x = x * enlarge_w / mask_w * -1const bg_y = y * enlarge_h / mask_h * -1bg.style.left = bg_x + 'px'bg.style.top = bg_y + 'px'
})</script></body></html>