100分扒一个回到顶部JS
http://www.cnblogs.com/lhb25/
那个很不错。
[解决办法]
function backTop(){
$(function(){
// hide #back-top first
$("#back-top").hide();
// fade in #back-top
$(function () {
$(window).scroll(function () {
if ($(this).scrollTop() > 500) {
$('#back-top').fadeIn();
} else {
$('#back-top').fadeOut();
}
});
// scroll body to 0px on click
$('#back-top a').click(function () {
$('body,html').animate({
scrollTop: 0
}, 800);
return false;
});
});
});
}
backTop();
<!DOCTYPE HTML>
<html>
<head>
<meta charset="gb2312" />
<title></title>
</head>
<body style="height:2000px;">
<script>
;(function(w, d){
var o = d.createElement('div');
d.getElementsByTagName('body')[0].appendChild(o);
o.style.cssText = 'display:none; position:absolute; top:0; right:10px; padding:0 4px 4px; width:12px; border:1px solid #6eaae5; color:#6eaae5; font-size:12px; cursor:pointer;';
o.innerHTML = '<div style="margin:0 0 4px 0; width:0; height:0; overflow:hidden; border:6px dashed transparent; border-bottom-style:solid; border-bottom-color:#6eaae5;"></div>回顶部';
o.onclick = function(){
w.scrollTo(0,0);
}
w.onscroll = function(){
var sTop = d.documentElement.scrollTop
[解决办法]
d.body.scrollTop;
sTop ? (o.style.display = 'block', o.style.top = sTop + 200 + 'px') : o.style.display = 'none';
}
})(window, document);
</script>
</body>
</html>