PS:javascript實現滾回頁面頂部!javascript
Javasciprt代碼:java
function goTopEx(){ide
var obj=document.getElementById("goTopBtn");spa
function getScrollTop(){ip
return document.documentElement.scrollTop;ci
}get
function setScrollTop(value){it
document.documentElement.scrollTop=value;io
} function
window.onscroll=function(){getScrollTop()>0?obj.style.display="":obj.style.display="none";}
obj.onclick=function(){
var goTop=setInterval(scrollMove,10);
function scrollMove(){
setScrollTop(getScrollTop()/1.1);
if(getScrollTop()<1)clearInterval(goTop);
}
}
}
HTMl代碼:
<body>
<div id="goTopBtn" style="display:none;">
<img width="52" height="52" border="0" src="lanren_top.jpg" >
</div>
<script type="text/javascript">
goTopEx();
</script>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
<p>a</p>
</body>