<!doctype html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>原生js懒加载</title>
<style type="text/css">
div{width:100px;height:100px;background:#F00;margin-bottom:30px}
</style>
</head>
<body>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/001.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/002.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/003.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/004.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/040.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/005.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/006.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/007.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/008.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/009.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/010.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/011.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/012.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/013.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/014.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/015.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/016.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/017.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/018.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/019.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/020.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/021.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/022.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/023.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/024.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/025.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/026.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/027.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/028.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/029.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/030.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/031.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/032.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/033.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/034.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/035.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/036.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/037.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/038.png
" src="a.gif" /></div>
<div><img asrc="http://www.pokemon.name/w/image/Sprites/PDW/039.png
" src="a.gif" /></div>
</body>
<script type="text/javascript">
(function(){
//common
function tagName(tagName){
return document.getElementsByTagName(tagName);
}
function $(id){
return document.getElementById(id);
}
// addEvent(window,'scroll',lazyLoad);
function addEvent(obj,type,func){
if(obj.addEventListener){
obj.addEventListener(type,func,false);
}else if(obj.attachEvent){
obj.attachEvent('on'+type,func);
}
}
//建立某些参数
var v={
eleGroup:null,
eleTop:null,
eleHeight:null,
screenHeight:null,
visibleHeight:null,
scrollHeight:null,
scrolloverHeight:null,
limitHeight:null
}
//对数据进行初始化
function init(element){//先让第一屏显示
v.eleGroup=tagName(element)
screenHeight=document.documentElement.clientHeight;//可视区域高度
scrolloverHeight=document.body.scrollTop;//距离顶部滚动的像素
for(var i=0,j=v.eleGroup.length;i<j;i++){
if(v.eleGroup[i].offsetTop<=screenHeight && v.eleGroup[i].getAttribute('asrc')){
v.eleGroup[i].setAttribute('src',v.eleGroup[i].getAttribute('asrc'));
v.eleGroup[i].removeAttribute('asrc')
}
}
}
function lazyLoad(){
if(document.body.scrollTop == 0){
limitHeight=document.documentElement.scrollTop+document.documentElement.clientHeight;
}else{
limitHeight=document.body.scrollTop+document.documentElement.clientHeight;
}
for(var i=0,j=v.eleGroup.length;i<j;i++){
if(v.eleGroup[i].offsetTop<=limitHeight && v.eleGroup[i].getAttribute('asrc')){
v.eleGroup[i].src=v.eleGroup[i].getAttribute('asrc');
v.eleGroup[i].removeAttribute('asrc')
}
}
}
init('img')
addEvent(window,'scroll',lazyLoad);
})()
</script>
</html>
