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HTML5計時器小例子
聽到計時器之後或許大家認為只有在js中可以實現，其實這種想法在你不知道有html5的情況下還能成立，下文為大家介紹下html5中是如何實現計時器的，感興趣的朋友不要錯過
html:
復制代碼 代碼如下:<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<!-- Always force latest IE rendering engine (even in intranet) & Chrome Frame
Remove this if you use the .htaccess -->
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>HTML5 Timer for work-relax balance</title>
<meta name="description" content="">
<meta name="author" content="kevin">
<meta name="viewport" content="width=device-width; initial-scale=1.0">
<!-- Replace favicon.ico & apple-touch-icon.png in the root of your domain and delete these references -->
<link rel="shortcut icon" href="/favicon.ico"/>
<link rel="apple-touch-icon" href="/apple-touch-icon.png"/>
<link rel="stylesheet" type="text/css" href="css/style.css">
<script>
countDownSeconds = 60;
var handle = null;
//window load
function onLoadWindow() {
aCanvas = document.getElementById("countdownCanvas");
context = aCanvas.getContext("2d");
var canvasText = "Press to Start...";
var xPos = aCanvas.width / 2;
var yPos = aCanvas.height / 2;
context.font = "12pt Century Gothic";
context.fillStyle = "#008000;";
context.textAlign = "center";
context.textBaseline = "middle";
context.fillText(canvasText, xPos, yPos);
}
function updateCanvas(theContext, width, height) {
if (countDownSeconds < 0) {
clearInterval(handle);
handle = null;
alert("hey, time is up!");
return 0;
}
minStr = Math.floor(countDownSeconds / 60);
secStr = countDownSeconds % 60;
if (minStr < 10) {
minStr = "0" + minStr;
}
if (secStr < 10) {
secStr = "0" + secStr;
}
context.clearRect(0, 0, width, height);
context.font = "24pt Century Gothic";
context.fillText(minStr + " : " + secStr, width / 2, height / 2);
countDownSeconds--;
}
function startWorkCountDown() {
if (handle != null) {
clearInterval(handle);
}
countDownSeconds = document.getElementById("workIntervalInput").value * 60;
timeDisplayCanvas = document.getElementById("countdownCanvas");
timeDisplayContext2D = timeDisplayCanvas.getContext("2d");
updateCanvas(timeDisplayContext2D, timeDisplayCanvas.width, timeDisplayCanvas.height);
handle = setInterval(function() {
updateCanvas(timeDisplayContext2D, timeDisplayCanvas.width, timeDisplayCanvas.height);
}, 1000);
}
function startRestCountDown() {
if (handle != null) {
clearInterval(handle);
}
countDownSeconds = document.getElementById("restIntervalInput").value * 60;
timeDisplayCanvas = document.getElementById("countdownCanvas");
timeDisplayContext2D = timeDisplayCanvas.getContext("2d");
updateCanvas(timeDisplayContext2D, timeDisplayCanvas.width, timeDisplayCanvas.height);
handle = setInterval(function() {
updateCanvas(timeDisplayContext2D, timeDisplayCanvas.width, timeDisplayCanvas.height);
}, 1000);
}
</script>
</head>
<body onload="onLoadWindow()">
<div align="center">
<header>
<h1>work-life balance timer</h1>
</header>
Please choose the work interval:
<input name="workIntervalInput" id="workIntervalInput" type="number" value="25" min="15" max="45" step="5"/>
minutes
Please choose the rest interval:
<input name="restIntervalInput" id="restIntervalInput" type="number" value="5" min="3" max="10" step="1"/>
minutes
<canvas id="countdownCanvas" width="300" height="50" style="border:2px solid black">
This is a canvas
</canvas>
<button onclick="startWorkCountDown()">
Work Hard
</button>
<button onclick="startRestCountDown()">
Take A Break
</button>
<footer>
<p>
© Copyright Reserved
</p>
</footer>
</div>
</body>
</html>
css3:
/*
* HTML5 ✰ Boilerplate
*
* What follows is the result of much research on cross-browser styling.
* Credit left inline and big thanks to Nicolas Gallagher, Jonathan Neal,
* Kroc Camen, and the H5BP dev community and team.
*
* Detailed information about this CSS: h5bp.com/css
*
* ==|== normalize ==========================================================
*/
/* =============================================================================
HTML5 display definitions
========================================================================== */
article, aside, details, figcaption, figure, footer, header, hgroup, nav, section { display: block; }
header {text-shadow: #220000 0px 0px 10px 10px;}
audio, canvas, video { display: inline-block; *display: inline; *zoom: 1; }
audio:not([controls]) { display: none; }
[hidden] { display: none; }
/* =============================================================================
Base
========================================================================== */
/*
* 1. Correct text resizing oddly in IE6/7 when body font-size is set using em units
* 2. Force vertical scrollbar in non-IE
* 3. Prevent iOS text size adjust on device orientation change, without disabling user zoom: h5bp.com/g
*/
html { font-size: 100%; overflow-y: scroll; -webkit-text-size-adjust: 100%; -ms-text-size-adjust: 100%; }
body { margin: 0; font-size: 24px; line-height: 1.231;}
body, button, input, select, textarea {font-family:"Century Gothic"; color:#008000}
/*
* Remove text-shadow in selection highlight: h5bp.com/i
* These selection declarations have to be separate
* Also: hot pink! (or customize the background color to match your design)
*/
::-moz-selection { background: #fe57a1; color: #fff; text-shadow: none; }
::selection { background: #fe57a1; color: #fff; text-shadow: none; }
/* =============================================================================
Links
========================================================================== */
a { color: #00e; }
a:visited { color: #551a8b; }
a:hover { color: #06e; }
a:focus { outline: thin dotted; }
/* Improve readability when focused and hovered in all browsers: h5bp.com/h */
a:hover, a:active { outline: 0; }
/* ==========
