标签：ntb += 高度 创建 new parse 更新 load active
window.onload = function () {
var d1 = new Waterfall();
d1.init();
};
//构造函数
function Waterfall() {
this.oColNum =null;//显示列数
this.oData = null; //存储请求数据
this.settings ={
width:300,
autoLoad:true
}
}
//初始化方法
Waterfall.prototype.init = function (opt) {
extend(this.settings,opt);
this.requestData();
var that = this;
window.onresize = function(){
that.init();
};
//滚动无限加载
if(this.settings.autoLoad){
// var that = this;
window.onscroll = function(){
if(getScrollTop() + getWindowHeight() == getScrollHeight()){
that.recreateEle();
}
};
}
};
//创建item
Waterfall.prototype.createItem = function (Data) {
var owater = document.getElementById("water-content");
var html="";
this.oData = Data;
var _this = this;
// console.log(this.oData.waterfall);
this.oData.waterfall.forEach(function (item,index) {
html +=‘<div class="waterfall-item" style="width: ‘+_this.settings.width+"px"+‘"><div class="waterfall-img"><img class="waterfall-images" src="‘+item.src+‘"></div><div class="info"><span>‘+item.name+‘</span></div></div>‘;
});
owater.innerHTML=html;
};
//请求获取数据
Waterfall.prototype.requestData =function () {
var xmlhttp;
var data=null;
var _this=this;
if (window.XMLHttpRequest)
{
// IE7+, Firefox, Chrome, Opera, Safari 浏览器执行代码
xmlhttp=new XMLHttpRequest();
}
else
{
// IE6, IE5 浏览器执行代码
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
data=eval(‘(‘ +xmlhttp.responseText+ ‘)‘);
//渲染数据
_this.createItem(data);
//存储img的src
var src =document.getElementsByClassName("waterfall-images");
//循环遍历创建 new Image；对象，保证onload事件执行，以获取加载img的div高度
for(var i = 0; i<src.length;i++){
var img = new Image();
img.onload =function () {
// console.log(img.src);
//设置位置样式
_this.setWaterfall();
};
img.src = src[i].src;
}
}
};
xmlhttp.open("GET","waterfall.json",true);
xmlhttp.send();
};
//排版布局
Waterfall.prototype.setWaterfall = function () {
this.oColNum = parseInt(viewWidth()/this.settings.width);
var oColNumHeight = [];//存储每一列的高度
for(var i = 0;i<this.oColNum;i++){
oColNumHeight.push(0);
}
var items =document.getElementsByClassName("waterfall-item");
//遍历设置元素位置
for(var i = 0; i < items.length; i++){
var curEle = items[i],
idx = 0;//存储最小值对应索引
var minHeight = oColNumHeight[0];//临时存储最小高度
//获取最小高度，以放置元素
for(var j = 0; j < oColNumHeight.length; j++){
if( minHeight >oColNumHeight[j]){
minHeight = oColNumHeight[j];
idx = j;
}
}
//设置元素位置
curEle.style.left = curEle.offsetWidth * idx +"px";
curEle.style.top = minHeight + "px";
// //更新每列的高度数据
oColNumHeight[idx] = oColNumHeight[idx]+ curEle.offsetHeight;
}
// for (var i = 0; i<items.length ;i++){
// items[i].className = ‘waterfall-item‘;
// }
// items.forEach(function (item,index) {
// var curEle = item,
// idx =0,
// minHeight = that.oColNumHeight[0];
// for(var i = 0; i<that.oColNumHeight.length;i++){
// if(minHeight>that.oColNumHeight[i]){
// minHeight = that.oColNumHeight[i];
// idx = i;
// }
// }
// curEle.style.left = that.settings.width*idx +"px";
// curEle.style.top = minHeight + "px";
// that.oColNumHeight[idx] = minHeight + curEle.style.height;
//
// })
};
//滚动无限加载
Waterfall.prototype.recreateEle = function () {
var dataSrc = {
"data":[
{
"src":"1.jpg",
"name":"重加载！"
},
{
"src":"5.jpg",
"name":"重加载！"
},
{
"src":"3.jpg",
"name":"重加载！"
},
{
"src":"6.jpg",
"name":"重加载！"
},
{
"src":"9.jpg",
"name":"重加载！"
},
{
"src":"8.jpg",
"name":"重加载！"
},
{
"src":"1.jpg",
"name":"重加载！"
},
{
"src":"5.jpg",
"name":"重加载！"
},
{
"src":"3.jpg",
"name":"重加载！"
},
{
"src":"6.jpg",
"name":"重加载！"
},
{
"src":"9.jpg",
"name":"重加载！"
},
{
"src":"8.jpg",
"name":"重加载！"
}
]
};
var _this =this;
var oDiv = document.getElementById("water-content");
// <div class="waterfall-img"><img class="waterfall-images" src="‘+item.src+‘"></div><div class="info"><span>‘+item.name+‘</span></div>
//创建加载的元素
for (var i = 0; i < dataSrc.data.length;i++){
var oItem = document.createElement("div");
oItem.className = "waterfall-item";
oItem.style.width = _this.settings.width +‘px‘;
oDiv.appendChild(oItem);
var oItemImg = document.createElement("div");
oItemImg.className = ‘waterfall-img‘;
oItem.appendChild(oItemImg);
var oImg = document.createElement("img");
oImg.className = ‘waterfall-images‘;
oImg.src =dataSrc.data[i].src;
oItemImg.appendChild(oImg);
var oInfoDiv = document.createElement("div");
oInfoDiv.className = ‘info‘;
oItem.appendChild(oInfoDiv);
var oSpan = document.createElement("span");
oSpan.innerHTML = dataSrc.data[i].name;
oInfoDiv.appendChild(oSpan);
}
//存储img的src
var src =document.getElementsByClassName("waterfall-images");
// console.log(src);
//循环遍历创建 new Image；对象，保证onload事件执行，以获取加载img的div高度
for(var i = src.length - 1; i > src.length - dataSrc.data.length;i--){
var img = new Image();
img.onload =function () {
//设置位置样式
_this.setWaterfall();
// console.log(‘.....‘)
};
img.src = src[i].src;
}
};
//获取浏览器可视宽度
function viewWidth() {
return document.documentElement.clientWidth;
}
//实现复制
function extend(obj1,obj2) {
for(var attr in obj2){
obj1[attr] = obj2[attr];
}
}
//滚动条在Y轴上的滚动距离
function getScrollTop(){
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;
}
//文档的总高度
function getScrollHeight(){
var scrollHeight = 0, bodyScrollHeight = 0, documentScrollHeight = 0;
if(document.body){
bodyScrollHeight = document.body.scrollHeight;
}
if(document.documentElement){
documentScrollHeight = document.documentElement.scrollHeight;
}
scrollHeight = (bodyScrollHeight - documentScrollHeight > 0) ? bodyScrollHeight : documentScrollHeight;
return scrollHeight;
}
//浏览器视口的高度
function getWindowHeight(){
var windowHeight = 0;
if(document.compatMode == "CSS1Compat"){
windowHeight = document.documentElement.clientHeight;
}else{
windowHeight = document.body.clientHeight;
}
return windowHeight;
}
标签：ntb += 高度 创建 new parse 更新 load active
原文地址：https://www.cnblogs.com/chenjianbao/p/9969663.html
