首先实现滚动要借助onscroll事件处理程序。
无穷滚动就是滑动滚动条，实现数据块的无穷加载。
我们以瀑布流的布局来实现无穷加载。瀑布流就是一些等宽不等高的数据块布局。在滚动条下拉时，它会进行加载。那么问题就是在判断什么时候应该加载。
我们首先应该明白瀑布流布局的特点。它将下一个图片总是放在当前列数最低的那一列。所以当加载最后一个蓝色的图片时，也就无疑是最后一个图片了。所以要判断该图片加载到什么程度来触发滚动事件。
图上灰色的表示页面的大小，后面蓝色边框表示窗口的大小。当拖动滚动条时，灰色部分上移。我们希望页面最后一个图片（蓝色图片）加载一半时触发滚动事件。那么就要形成参照。
下来写代码：
//检测是否具备滚动条加载数据块的条件 function checkScrollSlide(){ var oparent = document.getElementById('main'); var oBoxs = getByClass(oparent,'box'); var scrollH = document.body.scrollTop || document.documentElement.scrollTop + document.body.clientHeight || document.documentElement.clientHeight; var lastBoxH = oBoxs[oBoxs.length - 1].offsetTop + Math.floor(oBoxs[oBoxs.length - 1].offsetHeight/2); return (lastBoxH < scrollH )? true : false; }
getClass是根据类名查找元素集合的自己写的函数，待会儿会附上源码
我们要进行加载的数据块的格式是这样的.每个图片被一个class= pic的div包裹。最后整体属于父元素main
<div id = "main"> <div class = "box"> <div class = "pic"> <img src = "images/0.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/1.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/2.jpg"> </div> </div> <div>
首先我们要加载的数据块应该是从后台传过来的，在这里我们用json模拟一下就可以：
var DataIn = {"data":[{"src":'0.jpg'},{"src":'1.jpg'},{"src":'2.jpg'},{"src":'3.jpg'},{"src":'4.jpg'},{"src":'5.jpg'}]};
比如这个就是后台传过来的数据。
上面的函数返回一个布尔值，当为true时，触发滚动事件。
window.onscroll = function(){ var oparent = document.getElementById('main'); //当满足加载条件时，就要向页面中加载数据块 if(checkScrollSlide){ for(var i = 0; i< DataIn.data.length; i++){ var oBox = document.createElement('div'); oBox.className = 'box'; oparent.appendChild(oBox); var opic = document.createElement('div'); opic.className = 'pic'; oBox.appendChild(opic); var oImg = document.createElement('img'); oImg.src = './images/'+DataIn.data[i].src; opic.appendChild(oImg); } waterFull('main','box'); } } }
附上源码：
css和html
<!DOCTYPE html> <html> <head> <meta charset = "utf-8" /> <script src = "./jswaterfll.js"></script> <title>瀑布流布局</title> <style type="text/css"> *{ padding: 0px; margin: 0px; } #main{ position: relative; } .box{ /* display: inline-block;*/ padding: 15px 0px 0px 15px; float: left; } .pic{ padding: 10px; border-radius: 5px; border:1px solid #ccc; box-shadow: 0 0 5px #ccc; } .pic img{ width: 165px; height: auto; } </style> </head> <body> <div id = 'main'> <div class = "box"> <div class = "pic"> <img src = "images/3.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/4.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/20.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/21.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/2.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/3.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/4.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/5.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/6.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/7.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/8.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/9.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/10.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/11.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/17.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/18.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/19.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/4.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/5.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/6.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/7.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/8.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/11.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/12.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/13.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/14.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/15.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/16.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/17.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/18.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/19.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/20.jpg"> </div> </div> <div class = "box"> <div class = "pic"> <img src = "images/21.jpg"> </div> </div> </div> </body> </html>
js代码：