炫酷的返回顶部功能
js核心代码
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
返回顶部按钮的实现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;
}
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
}
请往下滑
以上所述就是本文的全部内容了,希望大家能够喜欢。