鼠标移入显示图片案例

在这里插入图片描述
<!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>
        ul {
            margin: 0;
            padding: 0;
            list-style: none;
            width: 509px;
            height: 509px;
            background-color: #ccc;
            position: relative;
        }
        
        .show li {
            float: left;
            width: 50px;
            height: 50px;
            position: absolute;
            top: 0;
            left: 0;
            background: url("./1.jpg");
            background-size: 509px 509px;
            opacity: 0;
            transition: all linear 0.6s;
        }
    </style>
</head>

<body>
    <ul class="show">

    </ul>
    <script>
        var ul = document.querySelector('.show');
        console.log(ul);
        var str = "";
        for (var i = 0; i < 100; i++) {
            str += '<li></li>';//用字符串拼接的的方法效率高
        }
        ul.innerHTML = str;
        var lis = ul.getElementsByTagName('li');
        for (var i = 0; i < lis.length; i++) {
        	//推理公式
            lis[i].style.left = i % 10 * 51 + "px";
            lis[i].style.top = Math.floor(i / 10) * 51 + "px";
            lis[i].style.backgroundPosition = `${-i%10*51}px ${-Math.floor(i/10)*51}px`
            lis[i].addEventListener('mouseover', function() {
                this.style.opacity = 1;
            })
        }
    </script>
</body>

</html>
原文链接：https://blog.csdn.net/weixin_45773503/article/details/112858788