倒计时javascript实现
代码如下:
1 /**
2 * 倒计时
3 *
4 * @author WadeYu
5 * @date 2012-04-20 17:40
6 * @copyright boyaa.com
7 */
8 var TimeCountDown = function( initTime ){
9 var day = 0;
10 var hour = 0;
11 var minute = 0;
12 var second = 0;
13 var timerId = 0;
14 var self = this;
15 var fixInitTime = function(){
16 initTime = parseInt(initTime);
17 if ( isNaN(initTime) || initTime < 0 ){
18 initTime = 0;
19 }
20 };
21 var fixZero = function(num){
22 return num < 10 ? ('0'+num) : num;
23 };
24 var calc = function(){
25 showCallback.call(self, [fixZero(day), fixZero(hour), fixZero(minute), fixZero(second)]);
26 if ( day === 0 && hour === 0 && minute === 0 && second === 0){
27 self.stop();
28 } else {
29 if (hour === 0 && day > 0){
30 hour = 24;
31 day--;
32 }
33 if (minute === 0 && hour > 0){
34 minute = 60;
35 hour--;
36 }
37 if (second === 0 && minute > 0){
38 second = 59;
39 minute--;
40 } else {
41 second--;
42 }
43 timerId = window.setTimeout(function(){
44 calc();
45 }, 1000);
46 }
47 };
48 var showCallback = function(){
49 alert('Please set show callback functions!');
50 };
51 var init = function(){
52 fixInitTime();
53 if ( initTime > 0 ){
54 day = Math.floor( (initTime / (24*60*60)) );
55 initTime -= day * 24*60*60;
56 hour = Math.floor( initTime / (60*60) );
57 initTime -= hour * 60*60;
58 minute = Math.floor( initTime / 60 );
59 second = initTime - minute * 60;
60 }
61 };
62 this.start = function(){
63 calc();
64 };
65 this.stop = function(){
66 timerId && window.clearTimeout(timerId);
67 };
68 this.setShowCallback = function(fn){
69 typeof(fn) === 'function' ? (showCallback = fn) : '';
70 };
71 init();
72 };
示例如下:
<body>
<div id="timeCon"></div>
<script type="text/javascript">
var timeCountDown = new TimeCountDown(3 * 24 * 60 * 60);
timeCountDown.setShowCallback(function( obj ){ // [天, 小时, 分, 秒]
document.getElementById('timeCon').innerHTML = obj[0] + ":" + obj[1] + ":" + obj[2] + ':' + obj[3];
});
timeCountDown.start();
</script>
</body>
摘自 huan & ping
