JS--放大镜

最新推荐文章于 2025-01-13 04:19:12 发布

Super--rookie

最新推荐文章于 2025-01-13 04:19:12 发布

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分类专栏：前端 JS 文章标签： JS-放大镜

本文链接：https://blog.youkuaiyun.com/qq_37964302/article/details/86263063

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<!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">
    <title>Document</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        
        #small-box {
            float: left;
            position: relative;
        }
        
        #spa {
            position: absolute;
            top: 0px;
            left: 0px;
            width: 200px;
            height: 200px;
            background: rgba(255, 255, 255, 0.5);
            display: none;
        }
        
        #big-box {
            position: relative;
            width: 400px;
            height: 400px;
            overflow: hidden;
            display: none;
        }
        
        #big-box>img {
            position: absolute;
            /* display: none; */
        }
    </style>
</head>

<body>
    <div id="small-box">
        <img src="1.jpg" alt="">
        <span id="spa"></span>
    </div>
    <div id="big-box">
        <img id="big-img" src="2.jpg" alt="">
    </div>
    <script>
        var oSmallbox = document.getElementById("small-box");
        var oSpa = document.getElementsByTagName("span")[0]; //取标签名为span的数组中第一个元素
        var oBigbox = document.getElementById("big-box");
        var oImg = document.getElementById("big-img");
        oSmallbox.onmouseover = function() {
            oSpa.style.display = "block";
            oBigbox.style.display = "block";
        }
        oSmallbox.onmouseout = function() {
            oSpa.style.display = "none";
            oBigbox.style.display = "none";
        }
        oSmallbox.onmousemove = function(e) {
            oSpa.style.left = e.clientX - oSpa.offsetWidth / 2 + "px";
            oSpa.style.top = e.clientY - oSpa.offsetHeight / 2 + "px";

            if (oSpa.offsetLeft < 0) {
                oSpa.style.left = 0 + "px";
            }
            if (oSpa.offsetLeft >= oSmallbox.offsetWidth - oSpa.offsetWidth) {
                oSpa.style.left = oSmallbox.offsetWidth - oSpa.offsetWidth + "px";
            }
            if (oSpa.offsetTop < 0) {
                oSpa.style.top = 0 + "px";
            }
            if (oSpa.offsetTop >= oSmallbox.offsetHeight - oSpa.offsetHeight)
                oSpa.style.top = oSmallbox.offsetHeight - oSpa.offsetHeight + "px";

            //小的span的最大移动距离
            var small;
            small = oSmallbox.offsetWidth - oSpa.offsetWidth;
            smallY = oSmallbox.offsetHeight - oSpa.offsetHeight;
            //大的img的最大移动距离
            var big;
            big = oImg.offsetWidth - oBigbox.offsetWidth;
            bigY = oImg.offsetHeight - oBigbox.offsetHeight;
            var percent = oSpa.offsetLeft / oSpa.offsetWidth;
            var percentY = oSpa.offsetTop / oSpa.offsetHeight
            oImg.style.left = -big * percent + "px";
            oImg.style.top = -bigY * percentY + "px";


        }
    </script>
</body>

</html>