JavaScript 实现页面无限滚动加载

//检测滚动条是否滚动到页面底部
 function isScrollToPageBottom(){
 //文档高度
 var documentHeight = document.documentElement.offsetHeight;
 var viewPortHeight = getViewportSize().h;
 var scrollHeight = window.pageYOffset ||
  document.documentElement.scrollTop ||
  document.body.scrollTop || 0;

 return documentHeight - viewPortHeight - scrollHeight < 20;
 }

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>无限分页</title>
 <link rel="stylesheet" href="assets/css/index.css"/>
</head>
<body>
<div class="l-page">
 <ul id="list" class="list">
 </ul>
</div>
<script src="https://cdn.bootcss.com/jquery/3.1.0/jquery.min.js"></script>
<script src="js/jquery.mockjax.js"></script>
<script type="text/javascript" src="js/dataMock.js"></script>
<script type="text/javascript">
 //作为一个对象的w和h属性返回视口的尺寸
 function getViewportSize(w){
 //使用指定的窗口， 如果不带参数则使用当前窗口
 w = w || window;

 //除了IE8及更早的版本以外，其他浏览器都能用
 if(w.innerWidth != null)
  return {w: w.innerWidth, h: w.innerHeight};

 //对标准模式下的IE（或任意浏览器）
 var d = w.document;
 if(document.compatMode == "CSS1Compat")
  return {w: d.documentElement.clientWidth, h: d.documentElement.clientHeight};

 //对怪异模式下的浏览器
 return {w: d.body.clientWidth, h: d.body.clientHeight};
 }

 //检测滚动条是否滚动到页面底部
 function isScrollToPageBottom(){
 //文档高度
 var documentHeight = document.documentElement.offsetHeight;
 var viewPortHeight = getViewportSize().h;
 var scrollHeight = window.pageYOffset ||
  document.documentElement.scrollTop ||
  document.body.scrollTop || 0;

 return documentHeight - viewPortHeight - scrollHeight < 20;
 }

 //商品模板
 function getGoodsTemplate(goods){
 return "<li>" +
  "<div class='pic-wrap leftFloat'>" +
  "<img src='" + goods.pic + "'>" +
  "</div>" +
  "<div class='info-wrap leftFloat'>" +
  "<div class='info-name'><span>" + goods.name + "</span></div>" +
  "<div class='info-address'><span>" +　goods.address +"</span></div>" +
  "<div class='info-bottom'>" +
  "<div class='info-price leftFloat'><span>￥" + goods.price + "</span></div>" +
  "<div class='info-star leftFloat'><span>" + goods.star + "人推荐</span></div>" +
  "<div class='info-more leftFloat'><span>更多信息</span></div>" +
  "</div>" +
  "</div>" +
  "</li>";
 }

 //初始化的时候默给list加载100条数据
 $.ajax("http://localhost:8800/loadData?sessionId=" + (+ new Date)).done(function(result){
 if(result.status){
  var html = "";
  result.data.forEach(function(goods){
  html += getGoodsTemplate(goods);
  });
  $("#list").append(html);
 }
 });


 //加载数据
 function loadDataDynamic(){
 //先显示正在加载中
 if( $("#loadingLi").length === 0)
  $("#list").append("<li id='loadingLi' class='loading'>正在加载...</li>");
 else{
  $("#loadingLi").text("正在加载...").removeClass("space");
 }
 var loadingLi = document.getElementById("loadingLi");
 loadingLi.scrollIntoView();
 //加载数据,数据加载完成后需要移除加载提示
 var hasData = false, msg = "";
 $.ajax("http://localhost:8800/loadData?sessionId=" + (+ new Date)).done(function(result){
  if(result.status){
  if(result.data.length > 0){
   hasData = true;
   var html = "";
   result.data.forEach(function(goods){
   html += getGoodsTemplate(goods);
   });
   $("#list").append(html);
  }else{
   msg = "数据已加载到底了"
  }
  }
  $("#list").append(loadingLi);
 }).fail(function(){
  msg = "数据加载失败!";
  }).always(function(){
  !hasData && setTimeout(function(){
  $(document.body).scrollTop(document.body.scrollTop -40);
  }, 500);
  msg && $("#loadingLi").text(msg);
  //重新监听滚动
  setTimeout(watchScroll, 900);
  });
 }

 //如果滚动条滚动到页面底部，需要加载新的数据,并且显示加载提示
 function watchScroll(){
 if(!isScrollToPageBottom()){
  setTimeout( arguments.callee, 900);
  return;  }
 loadDataDynamic();
 }

 //开始检测滚动条
 watchScroll();
</script>
</body>
</html>

/**
 * 模拟接口.
 */
var i = 0, len = 200, addresses = ["四川", "北京", "上海", "广州", "深圳", "甘肃", "云南", "浙江", "青海", "贵州"];


function getData(){
 var size = Math.min(i + 50, len), arr = [];
 for(; i < size; i++){
 arr.push({
  name: "苹果" + (i % 10 + 1),
  pic: "assets/images/iphone" + (i % 10 + 1) + ".jpg",
  price: parseInt(Math.random() * 10000),
  star: parseInt(Math.random() * 1000),
  address: addresses[i % 10]
 })
 }

 return arr;
}

$.mockjax({
 url: 'http://localhost:8800/loadData*',
 responseTime: 1000,
 response: function(settings){
 this.responseText = {
  status: true,
  data: getData()
 }
 }
});