HTML CODE:
<a name="top" id="top"></a>
<div style="height:1500px; width:10px; background:#0099FF">asdf</div>
<a href="javascript:void(0)" onclick="goto_top()">返回页顶</a>
JS CODE:
<script language="javascript">
//<![CDATA[
var goto_top_type = -1;
var goto_top_itv = 0;
function goto_top_timer()
{
var y = goto_top_type == 1 ? document.documentElement.scrollTop : document.body.scrollTop;
var moveby = 15;
y -= Math.ceil(y * moveby / 100);
if (y < 0) {
y = 0;
}
if (goto_top_type == 1) {
document.documentElement.scrollTop = y;
}
else {
document.body.scrollTop = y;
}
if (y == 0) {
clearInterval(goto_top_itv);
goto_top_itv = 0;
}
}
function goto_top()
{
if (goto_top_itv == 0) {
if (document.documentElement && document.documentElement.scrollTop) {
goto_top_type = 1;
}
else if (document.body && document.body.scrollTop) {
goto_top_type = 2;
}
else {
goto_top_type = 0;
}
if (goto_top_type > 0) {
goto_top_itv = setInterval('goto_top_timer()', 50);
}
}
}
//]]>
</script>
讨论数量：1
HTML CODE:
<div class="main">头部在这里哦！！</div>
<div id="gotopbtn">返回顶部</div>
JS CODE:
<script type="text/javascript">
backTop=function (btnId){
var btn=document.getElementById(btnId);
var d=document.documentElement;
window.onscroll=set;
btn.onclick=function (){
btn.style.display="none";
window.onscroll=null;
this.timer=setInterval(function(){
d.scrollTop-=Math.ceil(d.scrollTop*0.1);
if(d.scrollTop==0) clearInterval(btn.timer,window.onscroll=set);
},10);
};
function set(){btn.style.display=d.scrollTop?'block':"none"}
};
backTop('gotopbtn');
</script>
