lovecoding
/
W250511


			
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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">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        .small-img{
            width: 400px;
            height: 400px;
            position: relative;
            float: left;
        }
        .small-img img{
            width: 100%;
            height: 100%;
        }
        .small-img .mask{
            width: 200px;
            height: 200px;
            background-color: rgba(255,255,255,0.5);
            position: absolute;
            top: 0;
            left: 0;
        }
        .big-img{
            width: 400px;
            height: 400px;
            float: left;
            overflow: hidden;
            margin-left: 20px;
            position: relative;
        }
        .big-img img{
            width: 800px;
            height: 800px;
            position: absolute;
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="small-img">
            <img src="./image/niu.png" alt="img">
            <div class="mask"></div>
        </div>
        <div class="big-img">
            <img id="big-bg" src="./image/niu.png" alt="img">
        </div>
    </div>
    <script>
        // 第一步获取元素
        // 获取小图内的透明蒙版
        var oMask = document.getElementsByClassName("mask");
        oMask = oMask[0];
        // 获取小图区域
        var oSmallImg = document.getElementsByClassName("small-img");
        oSmallImg = oSmallImg[0];
        // 获取大图片
        // var oBigImg = document.getElementsByClassName("big-img");
        // oBigImg = oBigImg[0];
        var oBigImg = document.getElementById("big-bg");


        // 第二步给小图区域绑定鼠标移动事件
        oSmallImg.onmousemove = function(e){
            var x = e.clientX-100;
            var y = e.clientY-100;

            // 判断蒙版是否越界
            if(x>200){
                x = 200
            }
            if(y>200){
                y = 200
            }
            if(x<0){
                x=0
            }
            if(y<0){
                y=0
            }


            // 设置半透明蒙版的位置
            oMask.style.left = x + "px";
            oMask.style.top = y + "px";

            // 控制大图的移动
            oBigImg.style.left = (-2*x) + "px";
            oBigImg.style.top = (-2*y) + "px";
        }

    </script>
</body>
</html>