原生 js 时钟实现

<!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>
        * {
            padding: 0;
            margin: 0;
            box-sizing: border-box
        }

        ul,
        li {
            list-style: none;
        }

        .clock-box {
            position: absolute;
            width: 200px;
            height: 200px;
            top: 50%;
            left: 50%;
            margin-top: -100px;
            margin-left: -100px;
        }

        .clock-box:after {
            content: '';
            width: 10px;
            height: 10px;
            position: absolute;
            top: 50%;
            left: 50%;
            margin-top: -5px;
            margin-left: -5px;
            background: rebeccapurple;
            border-radius: 5px;
        }

        .clock-box .tick-box {
            position: relative;
            width: 100%;
            height: 100%;
            border: 2px solid black;
            border-radius: 50%;
        }

        .clock-box .tick-box li {
            position: absolute;
            height: 2px;
            width: 5px;
            top: 97px;
            left: -2px;
            background-color: #000;
            transform-origin: 100px center;
        }

        .clock-box .tick-box li:nth-child(5n+1) {
            width: 10px;
        }

        .item {
            position: absolute;
            background-color: red;
            transform-origin: center bottom;
        }

        .seconds-hand  {
            height: 89px;
            width: 1px;
            top: 11px;
            left: 99px;
            transform: rotate(0deg)
        }

        .minutes-hand {
            height: 76px;
            width: 2px;
            top: 24px;
            left: 98px;
            transform: rotate(60deg);
            background: green;
        }

        .hours-hand {
            height: 60px;
            width: 4px;
            border-top-left-radius: 3px;
            border-top-right-radius: 3px;
            top: 40px;
            left: 96px;
            transform: rotate(72deg);
            background: blue
        }
    </style>
</head>

<body>
    <div class="clock-box">
        <ul class="tick-box">
        </ul>
        <div class="hours-hand item"></div>
        <div class="minutes-hand item"></div>
        <div class="seconds-hand item"></div>
    </div>
</body>
<script>
    const frag = document.createDocumentFragment();
    const tickBox = document.querySelector('.tick-box')
    const hour = document.querySelector('.hours-hand')
    const minute = document.querySelector('.minutes-hand')
    const second = document.querySelector('.seconds-hand')
    for (let i = 0; i < 60; i++) {
        let li = document.createElement('li');
        li.style.transform = `rotate(${i * 360 / 60}deg)`;
        frag.appendChild(li)
    }
    tickBox.appendChild(frag)

    function time() {
       const now = new Date();
       const h = now.getHours();
       const m = now.getMinutes();
       const s = now.getSeconds();
       hour.style.transform = `rotate(${(h+m/60)*30}deg)`
       minute.style.transform = `rotate(${(m+s/60)*6}deg)`
       second.style.transform = `rotate(${s*6}deg)`
    }
    time()
    setInterval(time, 1000)
</script>

</html>
效果如下：
猜你喜欢
