css怎样让背景充满整个屏幕

<!DOCTYPE html>
<html>
<head>
	<meta charset="UTF-8">
	<title>炫酷时钟</title>
	<style type="text/css">
		body{
			height: 100%;color: #51555c;
			background: url("./img/bg1.png") no-repeat;
                       			/* 背景图垂直、水平均居中 */
			background-position: center center;
			
			/* 背景图不平铺 */
			background-repeat: no-repeat;
			
			/* 当内容高度大于图片高度时,背景图像的位置相对于viewport固定 */
			background-attachment: fixed;
			
			/* 让背景图基于容器大小伸缩 */
			background-size: cover;
			
			/* 设置背景颜色,背景图加载过程中会显示背景色 */
			background-color: #464646;
		}
		img{
			display: inline-block;
			width: 28px;
			height: 50px;
			margin:0 4px;
		}
		.main_demo{
			width: 910px;
			min-height: 600px;
			margin:30px auto 0 auto;
		}
		.main_demo h2{
			text-align: center;
			padding: 10px;
			font-size: 40px;
			color: wheat;
		}
		.clock{
			width: 500px;
			padding: 40px;
			margin:2px auto;
		}

		.clock_right{
			text-align: right;
			margin:4px;
		}
	</style>
</head>
<body>
	<div class="main_demo">
		<div align="center">
			<h2>Js 炫酷时钟</h2>
		</div>
		<div class="clock">
			<!--10点-->
			<img src="" />
			<img src="" />
			:
			<!--40分-->
			<img src="" />
			<img src="" />
			:
			<!--*秒-->
			<img src="" />
			<img src="" />
			<br />
			<div class="clock_right">
				<!--2017年-->
				<img src="" />
				<img src="" />
				<img src="" />
				<img src="" />
				:
				<!--09月-->
				<img src="" />
				<img src="" />
				:
				<!--27日-->
				<img src="" />
				<img src="" />
			</div>
		</div>
	</div>

</body>
<script type="text/javascript">
	var imgs = document.getElementsByTagName('img');
	setInterval(getTime,1000);

	function getTime(){
		var _date = new Date();
		var year = _date.getFullYear();
		var month = _date.getMonth()+1;
		var day = _date.getDate();
		var hour = _date.getHours();
		var minutes = _date.getMinutes();
		var second = _date.getSeconds();
		var newDate = addZero(hour) + "" + addZero(minutes)+ "" + addZero(second)+""+addZero(year) + "" + addZero(month)+ "" + addZero(day)
			;
		console.log(newDate.length);
		for(var i = 0;i < newDate.length;i++){
			imgs[i].src = 'img/time_' + newDate[i] + '.png';
		}
	}

	getTime();

	function addZero(num){
		if(num < 10){
			num = "0" + num;
		}
		return num
	}
</script>
</html>
    

 

posted @ 2017-09-27 12:49  BluesQian  阅读(2648)  评论(0编辑  收藏  举报