本章给大家介绍如何使用css3与js实现动态时钟效果，有一定的参考价值，有需要的朋友可以参考一下，希望对你有所帮助。

先看看效果图：

首先,思考了一下页面的布局,大致需要4层p,最底层是一个表盘的背景图,然后其余3层分别是时针,分针,秒针的图层.

html代码如下：

变量名是随便起的,不要介意; class=center的这个p是表中心那个小黑点.

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时针是60*60*60s转一圈, 分针是60*60s转一圈, 秒针是60s转一圈, 所以css代码如下：

.dial{    width:600px;    height:600px;    margin:0 auto;    position: absolute;    border-radius: 50%;    overflow: hidden;    background-color: rgba(153,50,204,0.2);    background-image: url(img/表盘.jpg);    background-size: 100% 100%;}.bigp{    width:600px;    height:600px;    margin:0 auto;    position: absolute;    border-radius: 50%;    overflow: hidden;}.bigp>p{    position: absolute;    left:298px;    border-radius: 100px;}.bigp1{    animation: moves 60s steps(60) infinite;}.bigp1 .secondHand{    width:4px;    height:250px;    background-color: red;    top:50px;    left:298px;}.bigp2{    animation: moves 3600s steps(3600) infinite;}.bigp2 .minuteHand{    width:6px;    height:180px;    background-color: green;    top:120px;    left:297px;}.bigp3{    animation: moves 216000s steps(216000) infinite;}.bigp3 .hourHand{    width:8px;    height:160px;    background-color: orange;    top:140px;    left:296px;    border-radius: 100px;}.bigp .center{    top:290px;    left:290px;    width:20px;    height:20px;    background-color: black;    z-index: 2;}@keyframes moves{    from{ transform: rotateZ(0deg); }    to{ transform: rotateZ(360deg); }}

这一步做完后效果图是这个样子的:

然后用js计算当前时间,

var date = new Date();var hours = date.getHours();var minutes = date.getMinutes();var seconds = date.getSeconds();

然后计算当前每个针的旋转角度

var secondAngle = seconds;var minuteAngle = minutes * 60 + seconds;var hourAngle = (60/12) * ((hours%12) * 3600 + minuteAngle);

现在的思路就是:每个针会按照自己定的时间转一圈,初始角度也能知道,怎么组成一个显示当前时间的动态钟表呢?

刚开始的想法是让这3层p旋转对应的角度,然后再开始,后来一想不行,因为它还是固定的时间旋转一周,指针指向会有偏差,

现在需要的是页面进来的第一圈旋转固定角度,其余的按照原来固定的时间旋转一周就行了,

css3里面有一个animation-delay属性,它表示的意思是动画延迟,负数就表示提前开始(比如-5s就表示动画从第5s的时间开始),

刚好可以用到,让这几个指针提前开始对应的角度.

js代码如下：

hourHand.style.cssText = "animation-delay: -"+ hourAngle +"s";minuteHand.style.cssText = "animation-delay: -"+ minuteAngle +"s";secondHand.style.cssText = "animation-delay: -"+ secondAngle +"s";

最后自己再加了个动态时间在钟表的上面展示

完整代码：

<ｓｃｒｉｐｔ>var dateshow = document.getElementById("dateshow");var clock = {weeks: ["一", "二", "三", "四", "五", "六", "日"],getDate: function() {date = new Date();year = date.getFullYear();month = date.getMonth() + 1;day = date.getDate();hours = date.getHours();minutes = date.getMinutes();seconds = date.getSeconds();week = date.getDay(); // 星期dateText = year + "年" + month + "月" + clock.format(day) + "日 星期" + clock.formatnum(week) + " " +clock.format(hours) + ":" + clock.format(minutes) + ":" + clock.format(seconds);return dateText;},format: function(data) {if(data.toString().length == 1) {data = "0" + data;};return data;},formatnum: function(num) {return clock.weeks[num - 1];},showdate: function() {dateshow.innerText = clock.getDate();},go: function() {var secondHand = document.getElementById("secondHand");var minuteHand = document.getElementById("minuteHand");var hourHand = document.getElementById("hourHand");date = new Date();hours = date.getHours();minutes = date.getMinutes();seconds = date.getSeconds();var secondAngle = seconds;var minuteAngle = minutes * 60 + seconds;var hourAngle = (60 / 12) * ((hours % 12) * 3600 + minuteAngle);hourHand.style.cssText = "animation-delay: -" + hourAngle + "s";minuteHand.style.cssText = "animation-delay: -" + minuteAngle + "s";secondHand.style.cssText = "animation-delay: -" + secondAngle + "s";}}clock.go();clock.showdate();setInterval("clock.showdate()", 1000);