js 中的事件 (时分秒计时器，进度条, 动态图展）

一：时分秒计时器

	<!DOCTYPE html>
	<html>

	<head>
	<meta charset="UTF-8">
	<title></title>
	<script type="text/javascript">
	// 全局保存我们的计时器id， sec_count 用来计时，my_start 用来控制计时器运行状态
	var timer_id = -1;
	var sec_count = 0;
	var my_start = 0;

	function start() {
	//如果开始计时了返回什么也不做了
	if(my_start == 1) {
	return;
	}
	// var sec_count = 0;
	//如果没开始就修改计时器的运行状态
	my_start = 1;
	//创建计时器计时
	timer_id = setInterval(function() {
	//计数器加加
	sec_count++;
	//计算时分秒
	var sec = sec_count % 60;
	var minute = Math.floor(sec_count % 60 / 60);
	var hour = Math.floor(sec_count / 3600);
	//拿元素
	var sec_tag = document.getElementById("second");
	var minute_tag = document.getElementById("minute");
	var hour_tag = document.getElementById("hour");
	//设置元素值
	sec_tag.innerHTML = sec;
	minute_tag.innerText = minute;
	hour_tag.innerText = hour;
	}, 1000)
	}

	function pause() {
	//清空计时器
	clearInterval(timer_id);
	//重置我们的函数的运行状态
	my_start = 0;
	}
	</script>
	</head>

	<body>
	<span id="hour">00</span>时<span id="minute">00</span>分<span id="second">00</span>秒
	<button onclick="start()">计时</button>
	<button onclick="pause()">暂停</button>
	</body>

	</html>

二：进度条，以百分比动态显示

	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="UTF-8">
	<title></title>
	<style type="text/css">
	#progress{
	height: 50px;
	width: 0;
	background: red;
	}
	</style>
	<script type="text/javascript">
	onload = function (){
	var my_pro = document.getElementById("progress");
	var percent_tag = document.getElementById("percent");
	var width_count = 0;
	var timer_id = setInterval(function (){
	width_count += 10;
	if (width_count >=300){
	clearInterval(timer_id);
	}
	var percent = Math.ceil(width_count / 3);
	my_pro.style.width = width_count + "px";
	percent_tag.innerHTML = percent + "%";
	}, 1000)
	}
	</script>
	</head>
	<body>
	<p>进度条</p>
	<div id="progress">

	</div>
	<div id="percent">

	</div>
	</body>
	</html>

	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="UTF-8">
	<title></title>
	<style type="text/css">
	#show{
	height: 154px;
	width: 154px;
	}
	.show_img{
	height: 154px;
	width: 154px;
	}
	*{
	margin: 0px;
	padding: 0px;
	}
	</style>
	<script type="text/javascript">
	onload = function(){
	var imgs = document.getElementsByTagName("img");
	for(var i=1;i<imgs.length;i++){
	imgs[i].onmousemove = function(){
	//换图
	var src = this.src;
	imgs[0].src = src;
	}
	}
	}
	</script>
	</head>
	<body>
	<table border="1px">

	<tr>
	<td rowspan="3" colspan="3" id="show"><img src="img/big_4.jpg" class="show_img" /></td>
	<td><img src="img/big_1.jpg"/></td>
	<td><img src="img/big_10.jpg"/></td>
	</tr>
	<tr>
	<td><img src="img/big_11.jpg"/></td>
	<td><img src="img/big_2.jpg"/></td>
	</tr>
	<tr>
	<td><img src="img/big_3.jpg"/></td>
	<td><img src="img/big_5.jpg"/></td>
	</tr>
	<tr>
	<td><img src="img/big_6.jpg"/></td>
	<td><img src="img/big_7.jpg"/></td>
	<td><img src="img/big_8.jpg"/></td>
	<td><img src="img/big_9.jpg"/></td>
	<td><img src="img/small_11.jpg"/></td>
	</tr>

	</table>
	</body>
	</html>