用js实现放大镜效果

Z时代
2024-01-10
分类：IT

本文实例为大家分享了js实现放大镜效果的具体代码，供大家参考，具体内容如下

该放大区域用背景图片放大


<!DOCTYPE html>
<html lang="zh">
 <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">
 <title></title>
 <style type="text/css">
 body {
 height: 1200px;
 background-color: lightskyblue;
 }
 ul {
 margin: 0;
 padding: 0;
 list-style: none;
 }
 .itemarea {
 position: relative;
 width: 500px;
 height: 680px;
 border: 1px black solid;
 margin: 50px auto;
 }
 .itemarea .pic {
 margin-bottom: 15px;
 }
 .itemarea img {
 width: 500px;
 height: 600px;
 }
 .itemarea .pic .cover {
 position: absolute;
 left: 0;
 top: 0;
 width: 200px;
 height: 200px;
 background-image: url(img/7.png);
 opacity: 0.6;
 display: none;
 }
 .itemarea .list {
 display: flex;
 }
 .itemarea .list li {
 margin: auto;
 }
 .itemarea .list img {
 display: block;
 width: 50px;
 height: 50px;
 }
 .itemarea .detail {
 position: absolute;
 top: 0;
 left: 500px;
 /* 此处为放大2倍，显示框的大小是遮阴框宽高的2倍 */
 width: 400px;
 height: 400px;
 display: none;
 border: 1px black solid;
 background: url(img/1.PNG);
 /* 此处放大2倍，背景图片的宽高是左边显示图片的2倍 */
 background-size: 1000px 1200px;
 /* background-size: 200%; 或者这样写*/
 }
 .itemarea .list .current {
 border: 2px green solid;
 }
 </style>
 </head>
 <body>
 <div class="itemarea">
 <div class="pic">
 <img src="img/1.PNG">
 <div class="cover"></div>
 </div>
 <ul class="list">
 <li><img src="img/1.PNG"></li>
 <li><img src="img/2.PNG"></li>
 <li><img src="img/3.PNG"></li>
 <li><img src="img/4.PNG"></li>
 <li><img src="img/5.PNG"></li>
 <li><img src="img/6.PNG"></li>
 </ul>
 <div class="detail">
 </div>
 </div>
 <script type="text/javascript">
 /* 
 需求
 1，鼠标放入图片时候，会动态修改图片地址
 2，鼠标放入大图，会动态修改右边图片位置
 2.1显示图片的放大镜，
 2.2显示右边效果
 */
 var itemarea = document.querySelector(".itemarea");
 var list = document.querySelector(".list");
 /* 上面的大图片 */
 img = document.querySelector(".pic img");
 /* 所有的图片 */
 imgs = list.querySelectorAll("img");
 /* 主图片展示区域 */
 pic = document.querySelector(".itemarea .pic");
 /* 放大镜 */
 cover = document.querySelector(".cover");
 /* 放大的区域 */
 detail = document.querySelector(".detail");
 /* 监听事件，切换图片src */
 list.addEventListener("mousemove", function(e) {
 if (e.target.tagName == "IMG") {
  img.src = e.target.src;
  detail.style.backgroundImage = "url(" + e.target.src + ")";
  /* 遍历 所有边框都为空*/
  imgs.forEach(function(item) {
  item.className = "";
  })
  /* 选中的改变边框颜色*/
  e.target.className = "current";
 }
 })
 pic.addEventListener("mousemove", function(e) {
 /* 放大镜距离浏览器的距离 */
 var x = e.clientX;
 y = e.clientY;
 /* 图片框距离浏览器的距离 */
 cx = pic.getBoundingClientRect().left;
 cy = pic.getBoundingClientRect().top;
 tx = x - cx - 100;
 ty = y - cy - 100;
 if (tx < 0) {
  tx = 0;
 }
 if (ty < 0) {
  ty = 0;
 }
 /* 显示图片宽-遮阴框的宽 */
 if (tx >300) {
  tx = 300;
 }
 /* 显示图片高-遮阴框的高 */
 if (ty > 400) {
  ty = 400;
 }
 cover.style.left = tx + "px";
 cover.style.top = ty + "px";
 /* 根据遮阴框在盒子的移动距离百分比------对应放映框在大图片的移动距离百分比 */
 /* tx,ty/遮阴框的极限范围 */
 detail.style.backgroundPosition = tx / 300 * 100 + "%" + ty / 400 * 100 + "%";
 })
 /* 移除隐藏 */
 itemarea.onmouseout = function() {
 cover.style.display = "none";
 detail.style.display = "none"
 }
 itemarea.onmouseover = function() {
 cover.style.display = "block";
 detail.style.display = "block";
 }
 </script>
 </body>
</html>