滚动到底部更新数据是个很常见的需求，也是网站优化的一部分。
- 页面效果
pic1.png
- 第一次滚动到底部新加载数据
pic2.png
- 再滚动
pic3.png
- 源代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
li{width: 100px;height: 100px;background: #000;margin-bottom: 15px;color: #fff;text-align: center;}
</style>
<script src="./jquery.min.js"></script>
</head>
<body>
<ul class="ul-wrap">
<li>1</li>
<li>1</li>
<li>1</li>
<li>1</li>
<li>1</li>
<li>1</li>
<li>1</li>
<li>1</li>
<li>1</li>
<li>1</li>
</ul>
<div id="loadInfo"></div>
<script>
function randomColor(){
var color="#";
var colorArr=["0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"];
for(i=0;i<6;i++){
var cur=randomNum(15,0);
color+=colorArr[cur];
}
function randomNum(max,min){
return Math.floor(Math.random()*(max-min+1)+min)
}
return color;
}
//获取滚动高度、文档高度、浏览器视口高度
var heightFuns=function(){
//获取滚动高度
heightFuns.prototype.getScrollTop=function (){
var scrollTop=0,bodyScrollTop=0,documentScrollTop=0;
if(document.body){
bodyScrollTop=document.body.scrollTop;
}
if(document.documentElement){
documentScrollTop=document.documentElement.scrollTop;
}
scrollTop = (bodyScrollTop-documentScrollTop>0)?bodyScrollTop:documentScrollTop;
return scrollTop;
}
//获取文档的总高度
heightFuns.prototype.getScrollHeight=function (){
var scrollHeight=0,bodyScrollHeight=0,documentScrollHeight;
if(document.body){
bodyScrollHeight=document.body.scrollHeight;
}
if(document.documentElement){
documentScrollHeight=document.documentElement.scrollHeight;
}
scrollHeight=(bodyScrollHeight-documentScrollHeight>0)?bodyScrollHeight:documentScrollHeight;
return scrollHeight;
}
//获取浏览器视口的高度
heightFuns.prototype.getWindowHeight=function (){
var windowHeight=0;
if(document.compatMode == 'CSS1Compat'){
windowHeight=document.documentElement.clientHeight;
}else{
windowHeight=document.body.clientHeight;
}
return windowHeight;
}
}
function showData(){
$(".ul-wrap").append("<li>new</li>");
$("body").css("background",randomColor());
$("#loadInfo").html("");
}
$(function(){
var heightObj=new heightFuns();
window.onscroll=function(){
if(heightObj.getScrollTop()==heightObj.getScrollHeight()-heightObj.getWindowHeight()){
// setTimeout(showData,1000);
showData();
$("#loadInfo").html("正在加载...");
}
}
});
</script>
</body>
</html>
