图（1）
图（2）
代码如下：
<!doctype html> <html> <head> <meta charset="UTF-8"> <title>Title</title> <style> *{margin:0; padding:0;} body{ background:#000; text-align:center;} canvas{ background:#fff;} </style> <script> function toDou(iNum){ return iNum<10?'0'+iNum:''+iNum; } function d2a(n){ return n*Math.PI/180; } window.onload = function(){ var oC = document.getElementById('c1'); var gd = oC.getContext('2d'); var cx = oC.width/2, cy = oC.height/2; function clock(){ gd.clearRect(0,0,oC.width,oC.height); var oDate = new Date(); var H = oDate.getHours()%12; var M = oDate.getMinutes(); var S = oDate.getSeconds(); var MS = oDate.getMilliseconds(); drawArc(60,0,(H*30+M/60*30),'orange'); drawArc(80,0,(M*6+S/60*6),'purple'); drawArc(100,0,(S*6+MS/1000*6),'aqua'); var str = toDou(H)+':'+toDou(M)+':'+toDou(S); gd.font = '20px 微软雅黑'; gd.textAlign = 'center'; gd.textBaseline = 'middle'; gd.fillText(str,cx,cy); } clock() setInterval(clock,1); function drawArc(r,s,e,color){ color = color||'black'; gd.beginPath(); gd.arc(cx,cy,r,d2a(s-90),d2a(e-90),false); gd.strokeStyle = color; gd.lineWidth = 20; gd.stroke(); } }; </script> </head> <body> <canvas></canvas> </body> </html>