苹果手表表盘时钟与js圆周运动
实现结果
需求分析：
1、时钟时间按照北京时间进行显示;
2、时针、分针、秒针按照时钟运转标准进行运转；
3、小球跟随秒表围绕表盘进行圆周运动。
代码分析
1、html结构：时针、分针、秒针、小球分别用一个div，将他们一起放到一个大的div中；
2、css样式：表盘布局多使用相对定位与绝对定位，将表针与各时刻标刻移动到特定的位置；
3、js行为：为了实现动态获取时间，可以使用var now=new Date()，再利用定时器setInterval，实现每经过1s重新获取当前时间。
核心函数
时钟运动
function getTimeDeg(){
//获取当前时间，计算在时钟上，时、分、秒对应转动角度
var now=new Date();
var s=now.getSeconds();
var sDeg=s/60*360;
var m=now.getMinutes();
var mDeg=(m*60+s)/3600*360;
var h=now.getHours();
var hDeg=(h*3600+m*60+s)/(3600*12)*360;
divH.style.transform=`rotate(${hDeg}deg)`;
divM.style.transform=`rotate(${mDeg}deg)`;
divS.style.transform=`rotate(${sDeg}deg)`;
}
圆周运动
function circleMotion(){
var now=new Date();
var sball=now.getSeconds();
var saDeg=sball/60*360-90;
var r = 250;
var radian = saDeg*Math.PI/180;
var top = Math.cos(radian)*r;
var left = Math.sin(radian)*r;
ball.style.left= top+'px';
ball.style.top = left+'px';
}
完整源代码（复制可用）
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>表盘时钟</title>
<style>
#circle{
width: 500px;height: 500px;border-radius: 255px;
position: relative;top: 50px;left: 500px;
background: radial-gradient(black,grey);
border:#f7f7f7 10px solid;
box-shadow: 0px 0px 0px 2px #a3a4a6,0px 0px 0px 32px #dedfe1;
}
#ball{
width: 30px;height: 30px;border-radius: 15px;
background-color: red;position: absolute;
margin-top: 235px;margin-left: 235px;
z-index: 6;
}
#dian{
width: 40px;height: 40px;border-radius: 20px;
background-color:white;position: absolute;
margin-top: 230px; margin-left: 230px;
box-shadow:0px -15px 10px -7px #867c7c inset,0px 0px 2px 0px black ;
z-index: 6;
}
#h{
width:8px;height: 100px;background-color: white;
position: absolute;border-radius: 8px;left: 246px;top: 150px;
box-shadow:0px 0px 2px 1px #867c7c inset,0px 0px 1px 0px black ;
z-index: 3;
}
#m{
width:6px;height: 150px;background-color: white;
position: absolute;top: 100px;left: 247px;border-radius: 6px;
box-shadow:0px 0px 1px 0px #867c7c inset,0px 0px 1px 0px black ;
z-index: 4;
}
#s{
width:2px;height: 180px;background-color: red;
position: absolute;top: 70px;left: 249px;border-radius: 2px;
z-index: 5;
}
#s,#m,#h{
transform-origin: center bottom;
}
.tip{
width: 6px;height: 26px;border-radius: 3px;background-color: white;
position: absolute;box-shadow:0px 0px 2px 1px #867c7c inset,0px 0px 1px 0px black ;
}
#time1{
top: 34px;left: 372px;transform-origin:top center ;transform: rotate(30deg);
}
#time2{
top: 125px;left: 463px;transform-origin:top center ;transform: rotate(60deg);
}
#time3{
top: 230px;left: 475px;transform: rotate(90deg);
width: 10px;height: 40px;border-radius: 5px;
}
#time4{
top: 349px;left: 460px;transform-origin:bottom center ;transform: rotate(-60deg);
}
#time5{
top: 440px;left: 369px;transform-origin:bottom center ;transform: rotate(-30deg);
}
#time6{
top: 460px;left: 245px;width: 10px;height: 40px;border-radius: 5px;
}
#time7{
top: 440px;left: 122px;transform-origin:bottom center ;transform: rotate(30deg);
}
#time8{
top: 349px;left: 31px;transform-origin:bottom center ;transform: rotate(60deg);
}
#time9{
top: 230px;left: 15px;transform: rotate(90deg);
width: 10px;height: 40px;border-radius: 5px;
}
#time10{
top: 124px;left: 30px;transform-origin:top center ;transform: rotate(-60deg);
}
#time11{
top: 33px;left: 121px;transform-origin:top center ;transform: rotate(-30deg);
}
#time12{
top: 0px;left: 245px;
width: 10px;height: 40px;border-radius: 5px;
}
</style>
</head>
<body>
<div id="circle">
<div id="h"></div>
<div id="m"></div>
<div id="s"></div>
<div id="ball" class="tip"></div>
<div id="dian" class="tip"></div>
<div id="time1" class="tip"></div>
<div id="time2" class="tip"></div>
<div id="time3" class="tip"></div>
<div id="time4" class="tip"></div>
<div id="time5" class="tip"></div>
<div id="time6" class="tip"></div>
<div id="time7" class="tip"></div>
<div id="time8" class="tip"></div>
<div id="time9" class="tip"></div>
<div id="time10" class="tip"></div>
<div id="time11" class="tip"></div>
<div id="time12" class="tip"></div>
</div>
<script>
//获取div节点
var ball=document.getElementById("ball")
var divS=document.getElementById("s");
var divM=document.getElementById("m");
var divH=document.getElementById("h");
//调用函数，可删除，删除后需等待1s才能看到运转
getTimeDeg();
//设置间隔时间为1s的定时器，每1s运行一次函数
setInterval(getTimeDeg,1000);
//时间获取函数
circleMotion();
setInterval(circleMotion,1000);
//时钟运动
function getTimeDeg(){
//获取当前时间，计算在时钟上，时、分、秒对应转动角度
var now=new Date();
var s=now.getSeconds();
var sDeg=s/60*360;
var m=now.getMinutes();
var mDeg=(m*60+s)/3600*360;
var h=now.getHours();
var hDeg=(h*3600+m*60+s)/(3600*12)*360;
divH.style.transform=`rotate(${hDeg}deg)`;
divM.style.transform=`rotate(${mDeg}deg)`;
divS.style.transform=`rotate(${sDeg}deg)`;
}
//圆周运动
function circleMotion(){
var now=new Date();
var sball=now.getSeconds();
var saDeg=sball/60*360-90;
var r = 250;
var radian = saDeg*Math.PI/180;
var top = Math.cos(radian)*r;
var left = Math.sin(radian)*r;
ball.style.left= top+'px';
ball.style.top = left+'px';
}
</script>
</body>
</html>
