canvas 自适应圆形时钟绘制示例

基本信息

源码名称：canvas 自适应圆形时钟绘制示例

源码大小：3.30KB

文件格式：.html

开发语言：CSS

更新时间：2018-08-24

友情提示：（无需注册或充值，赞助后即可获取资源下载链接）

嘿，亲！知识可是无价之宝呢，但咱这精心整理的资料也耗费了不少心血呀。小小地破费一下，绝对物超所值哦！如有下载和支付问题，请联系我们QQ(微信同号)：813200300

本次赞助数额为： 2 元　

源码介绍

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Document</title>
</head>
<body>
<canvas id="drawing"></canvas>
<script>
var drawing = document.getElementById('drawing');
if(drawing.getContext){
    var cxt = drawing.getContext('2d');
    var W = drawing.width = 200;
    var H = drawing.height = 200;
    var R = W / 2;
    var cw = cxt.lineWidth = 0.1*R;
    function drawStatics(){
        cxt.save();
        cxt.translate(R,R);
        cxt.beginPath();
        cxt.lineWidth = 0.1*R;
        cxt.arc(0,0,R-cw/2,0,2*Math.PI,false);
        cxt.stroke(); 
                      
        cxt.beginPath();   
        cxt.font = 0.2 * R   'px 宋体';
        cxt.textAlign = 'center';
        cxt.textBaseline = 'middle';  
        var r1 = 0.8*R  - cw/2;   
        for(var i = 12; i > 0; i--){
            var radius = 2*Math.PI/12 * i   1.5*Math.PI;
            var x = Math.cos(radius) * r1;
            var y = Math.sin(radius) * r1;
            cxt.fillText(i,x,y);
        }

        cxt.beginPath();
        var r2 = 0.9*R - cw/2;
        for(var i = 0; i < 60; i  ){
            var radius = 2*Math.PI/60*i   1.5*Math.PI;
            var x = Math.cos(radius) * r2;
            var y = Math.sin(radius) * r2;
            cxt.beginPath();
            if(i%5 === 0){
              cxt.arc(x,y,cw/5,0,2*Math.PI,false);
            }else{
              cxt.arc(x,y,cw/8,0,2*Math.PI,false);
            }
            cxt.fill();
        }
        cxt.restore();
    }
    function drawDot(){
        cxt.save();
        cxt.translate(R,R);        
        cxt.beginPath();
        cxt.arc(0,0,cw/3,0,2*Math.PI,false);
        cxt.fillStyle = '#fff';
        cxt.fill();
        cxt.restore();
    }
    function drawSecond(second){
        cxt.save();
        cxt.translate(R,R);
        cxt.beginPath();
        var radius = 2*Math.PI/60 * second;
        cxt.rotate(radius);
        cxt.lineWidth = 2;
        cxt.moveTo(0,cw*2);
        cxt.lineTo(0,-0.8*R);
        cxt.strokeStyle = 'red';
        cxt.stroke();
        cxt.restore();
    }
    function drawMinute(minute,second){
        cxt.save();
        cxt.translate(R,R);
        cxt.beginPath();
        var radius = 2*Math.PI/60 * minute;
        var sRaiuds = 2*Math.PI/60/60 * second;
        cxt.rotate(radius   sRaiuds);
        cxt.lineWidth = 4;
        cxt.lineCap = 'round';
        cxt.moveTo(0,cw);
        cxt.lineTo(0,-(0.8*R - cw/2));
        cxt.stroke();
        cxt.restore();
    }
    function drawHour(hour,minute){
        cxt.save();
        cxt.translate(R,R);
        cxt.beginPath();
        var radius = 2*Math.PI/12 * hour;
        var mRaiuds = 2*Math.PI/12/60 * minute;
        cxt.rotate(radius   mRaiuds);
        cxt.lineWidth = 6;
        cxt.lineCap = 'round';
        cxt.moveTo(0,cw/2);
        cxt.lineTo(0,-(0.8*R - cw*2));
        cxt.stroke();
        cxt.restore();
    }    
    function draw(){
        cxt.clearRect(0,0,W,H);
        drawStatics();
        var now = new Date();
        drawHour(now.getHours(),now.getMinutes());
        drawMinute(now.getMinutes(),now.getSeconds());   
        drawSecond(now.getSeconds());
        drawDot();    
    }
    draw();
    setInterval(draw,500);
}
</script>  
</body>
</html>