Rumah > Artikel > hujung hadapan web > HTML5编程实战之一-实现HTML5时钟的示例代码分享
HTML5编程实战之一-实现HTML5时钟的示例代码分享
- 黄舟asal
- 2017-03-30 13:25:341649semak imbas
<!DOCTYPE html><html><head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>超酷HTML5时钟(作者：http://www.cnblogs.com/jscode/)</title>
<style type="text/css">
.time {
text-align: center;
width:400px;
font-family: "Book Antiqua",Palatino,serif;
font-size: 40px;
font-weight: bold;
text-shadow: 1px 1px 3px #333;
position:absolute;
}
.time em {
background: white;
position: absolute;
top: 5px;
left: 130px;
height: 18px;
width: 140px;
opacity: 0.4;
}
</style>
<script type="text/javascript">
var canvas, context;
function DrawClock() {
canvas = document.getElementById("canvas");
context = canvas.getContext("2d");
setInterval("drawbackground()", 1000);
} function drawbackground() {
var radius = Math.min(canvas.width / 2, canvas.height / 2) - 15;
var centerx = canvas.width / 2;
var centery = canvas.height / 2;
context.clearRect(0, 0, canvas.width, canvas.height);
context.save();
context.lineWidth = 15;
context.fillStyle = "#EFEFEF";
context.strokeStyle = "#000";
context.beginPath();
context.arc(centerx, centery, radius, 0, Math.PI * 2, 0);
context.fill();
context.stroke();
context.closePath();
context.restore();
for (var i = 0; i < 60; i++) {
context.save();
context.fillStyle = "#EFEFEF";
context.strokeStyle = "#000";
if (i % 5 == 0) {
context.lineWidth = 3;
}
context.beginPath();
context.moveTo(centerx, centery);
context.lineTo(centerx + (radius-6) * Math.cos(i * 6 * Math.PI / 180), centery - (radius-5) * Math.sin(i * 6 * Math.PI / 180));
context.fill();
context.stroke();
context.closePath();
context.restore();
}
context.moveTo(centerx, centery);
context.save();
context.fillStyle = "#EFEFEF";
context.strokeStyle = "#EFEFEF";
context.beginPath();
context.arc(centerx, centery, radius-15, 0, Math.PI * 2, 0);
context.fill();
context.stroke();
context.closePath();
context.restore();
var r = radius - 25;
context.font = "bold 20px 宋体";
Drawtext("1", centerx + (Math.cos(60 * Math.PI / 180) * r), centery - (Math.sin(60 * Math.PI / 180) * r));
Drawtext("2", centerx + (Math.cos(30 * Math.PI / 180) * r), centery - (Math.sin(30 * Math.PI / 180) * r));
Drawtext("3", centerx + (Math.cos(0 * Math.PI / 180) * r), centery - (Math.sin(0 * Math.PI / 180) * r));
Drawtext("4", centerx + (Math.cos(330 * Math.PI / 180) * r), centery - (Math.sin(330 * Math.PI / 180) * r));
Drawtext("5", centerx + (Math.cos(300 * Math.PI / 180) * r), centery - (Math.sin(300 * Math.PI / 180) * r));
Drawtext("6", centerx + (Math.cos(270 * Math.PI / 180) * r), centery - (Math.sin(270 * Math.PI / 180) * r));
Drawtext("7", centerx + (Math.cos(240 * Math.PI / 180) * r), centery - (Math.sin(240 * Math.PI / 180) * r));
Drawtext("8", centerx + (Math.cos(210 * Math.PI / 180) * r), centery - (Math.sin(210 * Math.PI / 180) * r));
Drawtext("9", centerx + (Math.cos(180 * Math.PI / 180) * r), centery - (Math.sin(180 * Math.PI / 180) * r));
Drawtext("10", centerx + (Math.cos(150 * Math.PI / 180) * r), centery - (Math.sin(150 * Math.PI / 180) * r));
Drawtext("11", centerx + (Math.cos(120 * Math.PI / 180) * r), centery - (Math.sin(120 * Math.PI / 180) * r));
Drawtext("12", centerx + (Math.cos(90 * Math.PI / 180) * r), centery - (Math.sin(90 * Math.PI / 180) * r));
context.save();
context.fillStyle="black";
context.beginPath();
context.arc(centerx,centery,10,0,Math.PI*2,0);
context.fill();
context.stroke();
context.closePath();
context.restore();
drawpoint(centerx, centery, radius);
}
function drawpoint(centerx, centery, radius) {
var date = new Date();
var h = date.getHours();
h = h < 13 ? h : h - 12;
var m = date.getMinutes();
var s = date.getSeconds();
var th = date.getHours() < 10 ? "0" + date.getHours() : date.getHours();
var tm = m < 10 ? "0" + m : m;
var ts = s < 10 ? "0" + s : s;
document.getElementById("currtime").innerHTML = th + ":" + tm + ":" + ts;
var hr = h * 30 * Math.PI / 180 + (m / 60) * 30 * Math.PI / 180 + 90 * Math.PI / 180;
var mr = m * 6 * Math.PI / 180 + s / 60 * 6 * Math.PI / 180 + 90 * Math.PI / 180;
var sr = s * 6 * Math.PI / 180 + 90 * Math.PI / 180;
context.save();
context.lineWidth = 5;
context.fillStyle = "darkgray";
context.strokeStyle = "black";
context.beginPath();
context.moveTo(centerx + 20 * Math.cos(hr), centery + 20 * Math.sin(hr));
context.lineTo(centerx - (radius - 120) * Math.cos(hr), centery - (radius - 120) * Math.sin(hr));
context.moveTo(centerx + 20 * Math.cos(mr), centery + 20 * Math.sin(mr));
context.lineTo(centerx - (radius - 80) * Math.cos(mr), centery - (radius - 80) * Math.sin(mr));
context.moveTo(centerx + 20 * Math.cos(sr), centery + 20 * Math.sin(sr));
context.lineTo(centerx - (radius - 50) * Math.cos(sr), centery - (radius - 50) * Math.sin(sr));
context.closePath();
context.fill();
context.stroke();
context.restore();
}
function Drawtext(text, x, y) {
context.save();
x -= (context.measureText(text).width / 2);
y += 9;
context.beginPath();
context.translate(x, y);
context.fillText(text, 0, 0);
context.restore();
}
window.onload = DrawClock; </script>
</head>
<body>
<h1>超酷HTML5时钟(作者：http://www.cnblogs.com/jscode/)</h1>
<canvas id="canvas" width="400px" height="400px">
</canvas>
<p class="time"><span id="currtime">00:00:00</span>
<em></em>
</p>
</body>
</html>
方法作用解释：
DrawClock方法取得Canvas上下文
drawbackground 方法主要是画时钟的背景部分：边框、文字、刻度线
drawpoint 方法用来画时、分、秒线
Drawtext 方法是添加文字的
Atas ialah kandungan terperinci HTML5编程实战之一-实现HTML5时钟的示例代码分享. Untuk maklumat lanjut, sila ikut artikel berkaitan lain di laman web China PHP!
Kenyataan：
Kandungan artikel ini disumbangkan secara sukarela oleh netizen, dan hak cipta adalah milik pengarang asal. Laman web ini tidak memikul tanggungjawab undang-undang yang sepadan. Jika anda menemui sebarang kandungan yang disyaki plagiarisme atau pelanggaran, sila hubungi admin@php.cn
Artikel sebelumnya：HTML5 Canvas实战之实现烟花效果的代码案例Artikel seterusnya：HTML5编程实战之二-使用动画的形式切换图片代码案例