学习了极客学院JavaScript瀑布流实例，实现鼠标下拉图片自动加载效果，和百度图片效果类似[http://image.baidu.com/channel/wallpaper](http://image.baidu.com/channel/wallpaper)。
[TOC]
- HTML
~~~
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<link rel="stylesheet" type="text/css" href="css/style.css">
<script type="text/javascript" src="js/app.js"></script>
</head>
<body>
<div id="container">
<div class="box">
<div class="box_img"> <img src="images/1.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/2.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/3.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/4.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/5.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/6.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/7.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/8.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/9.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/10.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/1.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/2.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/3.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/4.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/5.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/6.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/7.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/8.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/9.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/10.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/1.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/2.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/3.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/4.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/5.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/6.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/7.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/8.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/9.jpg" alt=""></div>
</div>
<div class="box">
<div class="box_img"> <img src="images/10.jpg" alt=""></div>
</div>
</div>
</body>
</html>
~~~
- CSS
~~~
*{
margin: 0px;
padding: 0px;
}
#container{
position: relative;
}
.box{
padding: 5px;
float: left;
}
.box_img{
padding: 5px;
border: 1px solid #cccccc;
box-shadow: 0 0 5px #ccc;
border-radius: 5px;
}
.box_img img{
width: 150px;
height:auto;
}
~~~
- js
~~~
window.onload=function(){
imgLocation("container","box");
var imgData={
"data":[
{"src":"2.jpg"},
{"src":"3.jpg"},
{"src":"4.jpg"},
{"src":"5.jpg"},
{"src":"6.jpg"},
{"src":"7.jpg"},
{"src":"8.jpg"},
]
};
window.onscroll=function(){
if (checkFlag()) {
var cparent=document.getElementById("container");
for (var i = 0; i < imgData.data.length; i++) {
var ccontent=document.createElement("div");
ccontent.className="box";
cparent.appendChild(ccontent);
var boximg=document.createElement("div");
boximg.className="box_img";
ccontent.appendChild(boximg);
var img=document.createElement("img");
img.src="images/"+imgData.data[i].src;
boximg.appendChild(img);
}
imgLocation("container","box");
}
}
}
function checkFlag(){
var cparent=document.getElementById("container");
var ccontent=getChildnode(cparent,"box");
var lastContentHeight=ccontent[ccontent.length-1].offsetTop;
var scrollTop=document.documentElement.scrollTop||document.body.scrollTop;
var pageHeight=document.documentElement.clientHeight||document.body.clientHeight;
if (lastContentHeight<scrollTop+pageHeight) {
return true;
}
}
function imgLocation(parent,content){
var cparent=document.getElementById(parent);
var ccontent=getChildnode(cparent,content);
var imgWidth=ccontent[0].offsetWidth;
var cols=Math.floor(document.documentElement.clientWidth/imgWidth);
cparent.style.cssText="width:"+imgWidth*cols+"px;margin:0 auto";
//把第二排的左起第一张图片放到第一排高度最小的那张下面
var imgHeightArr=[];
for (var i = 0; i < ccontent.length; i++) {
if (i<cols) {
imgHeightArr[i]=ccontent[i].offsetHeight;
}else{
var minHeight=Math.min.apply(null,imgHeightArr);
var minHeightIndex=getMinHeightLoc(imgHeightArr,minHeight);
console.log("minHeightIndex"+minHeightIndex);
ccontent[i].style.position="absolute";
ccontent[i].style.top=minHeight+"px";
ccontent[i].style.left=ccontent[minHeightIndex].offsetLeft+"px";
imgHeightArr[minHeightIndex]=imgHeightArr[minHeightIndex]+ccontent[i].offsetHeight;
console.log(imgHeightArr[i]);
console.log("高度最低:"+minHeight);
}
}
}
function getChildnode(parent,content){
var contentArr=[];
var allcontent=parent.getElementsByTagName("*");
for (var i = 0; i < allcontent.length; i++) {
if(allcontent[i].className==content){
contentArr.push(allcontent[i]);
}
};
return contentArr;
}
function getMinHeightLoc(imgHeightArr,minHeight){
for(var i in imgHeightArr){
if (imgHeightArr[i]==minHeight) {
return i;
}
}
}
~~~
- 实现效果
