会走动的图形会走动的图形html5时钟示例时钟示例
使用HTML5制作时钟
复制代码代码如下:
<!DOCTYPE html>
<html>
<head>
<title>html5时钟</title>
</head>
<body>
<canvas id = “canvas”></canvas></p>
<p> <script>
var Clock = function (canvas, options) {
this.canvas = canvas;
this.ctx = this.canvas.getContext(“2d”);
this.options = options;
};</p>
<p> Clock.prototype = {
constructor: Clock,
drawCircle: function () {
var ctx = this.ctx;
ctx.strokeStyle = “black”;
ctx.arc(this.canvas.width / 2, this.canvas.height / 2, 50, 0, 2 * Math.PI, false);
ctx.stroke();
},
drawNum: function () {
var ctx = this.ctx;
var angle = Math.PI * 2 / 12;
for (var i = 1; i <= 12; i += 1) {
ctx.font = “20px Georgia”;
ctx.textAlign = “center”;
ctx.textBaseline = ‘middle’;
ctx.fillText(String(i), this.canvas.width / 2 + Math.cos(3 *Math.PI / 2 + angle * i) * 40, this.canvas.height / 2 + Math.sin(3 *
Math.PI / 2 + angle * i) * 40);
}
},
drawPointer: function () {
var ctx = this.ctx;
var that = this;
var date, hour, minute, second;
date = new Date();
hour = date.getHours();
if (hour > 12) {
hour = hour % 12;
}
minute = date.getMinutes();
second = date.getSeconds();</p>
<p> var b = minute * Math.PI / 30;
var c = second * Math.PI / 30;
var a = hour * Math.PI / 6 + Math.PI / 6 * minute / 60;
var minuteAngle = Math.PI * 2 / 3600;
var secondAngle = Math.PI * 2 / 60;
var hourAngle = Math.PI * 2 / 12 / 3600;</p>
<p> ctx.beginPath();
ctx.save();
ctx.translate(that.canvas.width / 2, that.canvas.height / 2);
ctx.arc(0, 0, 3, 0, 2 * Math.PI, false);
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