<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>jquery返回顶部</title>
<style type="text/css">
.mainContent{
background: #ededed;
width: 960px;
height: 1000px;
margin: 0 auto;
}
.mainContent h3{
text-align: center;
padding:20px;
}
p#back-to-top{
position:fixed;
display:none;
bottom:100px;
right:80px;
}
p#back-to-top a{
text-align:center;
text-decoration:none;
color:#d1d1d1;
display:block;
width:64px;
/*使用CSS3中的transition属性给跳转链接中的文字添加渐变效果*/
-moz-transition:color 1s;
-webkit-transition:color 1s;
-o-transition:color 1s;
}
p#back-to-top span{
background: url(images/back-to-top.png);
background-repeat: no-repeat;
border-radius:6px;
display:block;
height:64px;
width:56px;
margin-bottom:5px;
/*使用CSS3中的transition属性给<span>标签背景颜色添加渐变效果*/
-moz-transition:background 1s;
-webkit-transition:background 1s;
-o-transition:background 1s;
}
</style>
<script src="http://code.jquery.com/jquery-1.10.2.min.js"></script>
</head>
<body>
<div class="mainContent">
<h3>演示返回顶部效果</h3>
</div>
<p id="back-to-top"><a href="#top"><span></span>返回顶部</a></p>
<script>
$(function() {
//当滚动条的位置处于距顶部100像素以下时，跳转链接出现，否则消失
$(window).scroll(function() {
if ($(window).scrollTop()>100) {
$("#back-to-top").fadeIn(1500);
}
else
{
$(‘#back-to-top‘).fadeOut(1500);
}
});
//当点击跳转链接后，回到页面顶部位置
$(‘#back-to-top‘).click(function() {
$(‘body,html‘).animate({scrollTop:0},1000);
return false;
})
})
</script>
</body>
</html>