如何使滚轮滚动时让div背景图片移动的相对缓慢些?
我想要想花瓣网背景图片一样的效果:http://huaban.com/
相关代码
// 请把代码文本粘贴到下方(请勿用图片代替代码)
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title> new document </title>
<script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script>
<script src="http://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
<style type="text/css">
body{
height: 2000px;background: #3867ff;
}
.bg {
background: url(http://hbfile.b0.upaiyun.com/img/home/banner/8b9b27958ec5005c566e9a8d1b663e561dad76effa888) center top no-repeat;
height: 408px;
}
</style>
</head>
<body>
<div class="bg" id="J_bg"></div>
<div id="bt" style="height: 500px;background: green"></div>
<script>
$(function(){
var $ele = $('#J_bg');
var height = $ele.height();
$(window).on('scroll', function(){
var scrollTop = -$(document.body).scrollTop()/ 2;
console.log(scrollTop)
var offset = scrollTop > height ? height : scrollTop;
$ele.css('background-position', "50%" +scrollTop+ 'px');
});
})
</script>
</body>
</html>