canvas時鐘純手寫
阿新 • • 發佈：2019-01-03
html程式碼：
<!DOCTYPE html> <html> <head> <title></title> <meta charset="utf-8"> <style type="text/css"> div{ text-align: center; margin-top: 250px; } #clock{ border:1px solid #ccc; } </style> </head> <body> <div> <canvas id="clock" width="300px" height="300px"></canvas> </div> </body> <script type="text/javascript" src="clock.js"></script> </html>
js程式碼：
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/2,0,2*Math.PI,false); ctx.stroke(); var hoursNumbers=[3,4,5,6,7,8,9,10,11,12,1,2]; ctx.font=18*rem+'px Arial'; ctx.textAlign="center"; ctx.textBaseline='middle'; hoursNumbers.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); 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 drawHour(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="#c14543"; var rad = 2*Math.PI/60*second; ctx.rotate(rad); ctx.moveTo(-2*rem,20*rem); ctx.lineTo(2*rem,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(); drawHour(hour,minute); drawMinute(minute); drawSecond(second); drawDot(); ctx.restore(); } draw(); setInterval(draw,1000);