HTML代码：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
<style type="text/css">
.colock_div{
margin-top: 10%;
margin-left: 40%;
/*border: 1px solid red;*/
}
.colock{
/*background-color: blue;*/
/*border: 1px solid red;*/
}
</style>
</head>
<body>
<div class="colock_div">
<canvas width="400" height="400" id="clock" class="colock">
</div>
</body>
<script type="text/javascript" src="js/colock.js"></script>
</html>
js 代码：
var dom = document.getElementById('clock');
var ctx = dom.getContext("2d");
var width = ctx.canvas.width;
var height = ctx.canvas.height;
var r = width / 2;
var rem = width /200;
function drawBackground() {
ctx.save();
ctx.translate(r,r);
ctx.beginPath();
ctx.lineWidth = 10*rem;
ctx.arc(0,0,r-ctx.lineWidth/2,2*Math.PI,false);
ctx.stroke();
var hourNumbers= [3,4,5,6,7,8,9,10,11,12,1,2];
ctx.font =18*rem+"px Arial";
ctx.textAlign = "center";
ctx.textBaseline = "middle";
hourNumbers.forEach(function(number,i){
var rad = 2 * Math.PI/12 * i;
var x = Math.cos(rad)*(r-40*rem);
var y = Math.sin(rad)*(r-40*rem);
ctx.fillText(number,x,y);
});
for (var i = 0 ; i<60;i++) {
var rad = 2 * Math.PI/60 * i;
var x = Math.cos(rad)*(r-18*rem);
var y = Math.sin(rad)*(r-18*rem);
ctx.beginPath();
if(i % 5 === 0){
ctx.fillStyle = "#000";
ctx.arc(x,y,2*rem,0,2*Math.PI,false);
}else{
ctx.fillStyle = "#ccc";
ctx.arc(x,y,2*rem,0,2*Math.PI,false);
}
ctx.fill();
}
}
function darwHour(hour,minute){
ctx.save();
ctx.beginPath();
var rad = 2* Math.PI / 12 *hour;
var mrad= 2* Math.PI / 12/60 *minute;
ctx.rotate(rad+mrad);
ctx.lineWidth = 6*rem;
ctx.lineCap = "round";
ctx.moveTo(0,10*rem);
ctx.lineTo(0,-r/2);
ctx.stroke();
ctx.restore();
}
function drawMinute(minute){
ctx.save();
ctx.beginPath();
var rad = 2* Math.PI /60 * minute;
ctx.rotate(rad);
ctx.lineWidth = 3*rem;
ctx.lineCap = "round";
ctx.moveTo(0,10*rem);
ctx.lineTo(0,-r+30*rem);
ctx.stroke();
ctx.restore();
}
function drawSecond(second){
ctx.save();
ctx.beginPath();
ctx.fillStyle = "#FF0000";
var rad = 2* Math.PI /60 * second;
ctx.rotate(rad);
ctx.moveTo(-2,20*rem);
ctx.lineTo(2,20*rem);
ctx.lineTo(1,-r+18*rem);
ctx.lineTo(-1,-r+18*rem);
ctx.fill();
ctx.restore();
}
function drawDot(){
ctx.beginPath();
ctx.fillStyle = "#fff";
ctx.arc(0,0,3,0,2*Math.PI,false);
ctx.fill();
}
function draw(){
ctx.clearRect(0,0,width,height);
var now = new Date();
var hour = now.getHours();
var minute = now.getMinutes();
var second = now.getSeconds();
drawBackground();
darwHour(hour,minute);
drawMinute(minute);
drawSecond(second);
drawDot();
ctx.restore();
}
draw()
setInterval(draw,1000);
