search

Home  >  Article  >  Web Front-end  >  Implementation of return to top button in javascript_javascript skills

Implementation of return to top button in javascript_javascript skills

WBOY
WBOYOriginal
2016-05-16 16:00:551137browse

Cool return to top function

js core code

window.onscroll = function(){ 
  var t = document.documentElement.scrollTop || document.body.scrollTop; 
  var top_div = document.getElementById( "go" ); 
  if( t >= 300 ) { 
    top_div.style.display = "block"; 
  } else { 
    top_div.style.display = "none"; 
  } 
} 
 
 
var ptt=20;
function pageScroll() {
 
document.getElementById('flypig').style.display='block';
window.scrollBy(0,-10); //每次上升10px
 
 
 
if(document.body.scrollTop==0) {  
  document.getElementById('flypig').style.marginBottom=ptt+'px';
  ptt=ptt+10; 
}
scrolldelay = setTimeout('pageScroll()',2); //2毫秒重复执行一次
 
if(ptt>=1000){
  ptt=0;
  document.getElementById('flypig').style.marginBottom=20+'px';
  document.getElementById('flypig').style.display='none';
  clearTimeout(scrolldelay);
}
//pageScroll ends
}

html

<!DOCTYPE html>
<html>
<head>
 <title>返回顶部按钮的实现</title>
 <meta charset="utf-8" />
<style>
body{
  margin:0px;
}
#flypig{
 display: none; 
 float: left; 
 position: fixed; 
 bottom: 20px; 
 margin-left: 75%; 
 cursor: pointer; 
 margin-bottom: 20px;
}
#go{
 display: block; 
 float: left; 
 position: fixed; 
 bottom: 10px; 
 margin-left: 75%; 
 cursor: pointer;
}
</style>
<script>
 
window.onscroll = function(){ 
  var t = document.documentElement.scrollTop || document.body.scrollTop; 
  var top_div = document.getElementById( "go" ); 
  if( t >= 300 ) { 
    top_div.style.display = "block"; 
  } else { 
    top_div.style.display = "none"; 
  } 
} 
 
var ptt=20;
function pageScroll() {
 
document.getElementById('flypig').style.display='block';
window.scrollBy(0,-10); //每次上升10px
 
if(document.body.scrollTop==0) {  
  document.getElementById('flypig').style.marginBottom=ptt+'px';
  ptt=ptt+10; 
}
scrolldelay = setTimeout('pageScroll()',2); //2毫秒重复执行一次
 
if(ptt>=1000){
  ptt=0;
  document.getElementById('flypig').style.marginBottom=20+'px';
  document.getElementById('flypig').style.display='none';
  clearTimeout(scrolldelay);
}
//pageScroll ends
} 
    
</script>
</head>
<body>
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<h1 style="text-align:center;">请往下滑</h1>
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br /><br />
<br />
<br />
<br />
<br /><br />
<br />
<br />
<br />
<br /><br />
<br />
<br />
<br />
<br /><br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br /><!--让你的页面足够的长-->
<div style="display: none; float: left; position: fixed; margin-left: 50%; cursor: pointer; margin-bottom: 20px;" id="flypig">
<img src="/wp-content/themes/Jakesoft/images/flypig.gif">    </div>
<div style="display: none; float: left; position: fixed; bottom: 10px; margin-left: 50%; cursor: pointer;" id="go" onclick="pageScroll()">返回顶部</div></html>

The above is the entire content of this article, I hope you all like it.

Statement：
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Previous article：JS method to calculate age based on birthday_javascript skillsNext article：JS method to calculate age based on birthday_javascript skills

Related articles

See more