canvas做钟表

来源：互联网发布：网络赌托该不该举报编辑：程序博客网时间：2024/05/17 02:38

<!DOCTYPE html>

<html>
<head>
<meta charset="utf-8">
<title>canvas做时钟</title>
<style type="text/css">
div{
text-align: center;
margin-top: 250px;
}
#clock{
border:1px solid #ccc;
}
</style>
</head>

<body >
<div>
<canvas id="clock" width="200px" height="200px"></canvas>
</div>
</body>
<script type="text/javascript">
var dom=document.getElementById("clock");
var context=dom.getContext("2d");
var width=context.canvas.width;
var height=context.canvas.height;
var r=width/2;
var rem=width/200;

function drawbackgroud(){
context.save();
context.translate(r,r);
context.beginPath();
context.lineWidth = rem * 4;
context.arc(0,0,r - context.lineWidth / 2,0,2 * Math.PI,false);
context.stroke();

var hour = [3,4,5,6,7,8,9,10,11,12,1,2];
context.font = 18*rem + 'px Aprial';
context.textAlign = 'center';
context.textBaseline = 'middle';

hour.forEach(function(number,i){
var rad = 2 * Math.PI / 12 * i;
var x = Math.cos(rad) * (r - 30 * rem);
var y = Math.sin(rad) * (r - 30 * rem);
context.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);
context.beginPath();
if(i%5===0) {
context.fillStyle="#000";
context.arc(x,y,2*rem,0,2*Math.PI,false);

} else {
context.fillStyle="#ccc";
context.arc(x,y,2*rem,0,2*Math.PI,false);
}
context.fill();

}

}

function drawHour(hour,minute){
context.save();
context.beginPath();
context.lineWidth=6*rem;
context.lineCap="round";
var rad = 2 * Math.PI/12*hour;
var mrad = 2 * Math.PI/12/60*minute;
context.rotate(rad + mrad );
context.moveTo(0,10 * rem);
context.lineTo(0,- r/2);
context.stroke();
context.restore();
}

function drawMinute(Minute){
context.save();
context.beginPath();

context.lineWidth=4*rem;
var rad = 2 * Math.PI / 60 * Minute;
context.rotate(rad);
context.lineCap="round";
context.moveTo(0,10 * rem);
context.lineTo(0,- r+ 30 *rem );
context.stroke();
context.restore();
}

function drawSecond(second){
context.save();
context.beginPath();
context.fillStyle= '#c14543'

var rad = 2 * Math.PI/60*second;
context.rotate(rad);
context.moveTo(-2,20);
context.lineTo(2,20);
context.lineTo(1,-r+18);
context.lineTo(-1,-r+18)
context.fill();
context.restore();
}

function drawDot(){
context.beginPath();
context.fillStyle="#fff";
context.arc(0,0,3,0,2*Math.PI,false);
context.fill();
}

function draw(){
context.clearRect(0,0,width,height);
var now = new Date();
var hour = now.getHours();
var Minute = now.getMinutes();
var second = now.getSeconds();
drawbackgroud();
drawHour(hour,Minute);
drawMinute(Minute);
drawSecond(second);
drawDot();
context.restore();
}
draw();
setInterval(draw,1000);
</script>
</html>

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