代码驿站移动版

当前位置：主页 > 网页前端 > JavaScript代码 >

web页面和微信小程序页面实现瀑布流效果

时间：2021-09-30 08:57:39 | 栏目：JavaScript代码 | 点击：次

小程序实现瀑布流效果，和web页面差不多，都要经过以下步骤：

1)、加载图片，获取图片的宽高度；

2)、根据页面需要显示几列计算每列的宽度；

3)、根据图片真实宽度和每列的宽度比，计算出图片需要显示的高度；

4)、重新对图片进行定位

　　1、web页面瀑布流效果，先看效果图（瀑布流+无限滚动加载）：

　页面代码：

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
  <meta charset='utf-8′> <!--声明文档使用的字符编码-->
  <title>瀑布流_左浮动</title>
 <style type="text/css">
  *{margin:0;padding:0;}
  .container {
   width: 1200px; height: auto; margin: 50px auto;
   position: relative;
  }
  .box{
   padding: 5px; box-shadow: 0 0 10px purple; border-radius: 5px;
   float: left; margin: 10px;
  }
  .box img { width: 200px; height: auto; }
 </style>
</head>
<body>
 <div class="container">
  <div class="box"><img src="../img/0.jpg"/></div>
  <div class="box"><img src="../img/1.jpg"/></div>
  <div class="box"><img src="../img/2.jpg"/></div>
  <div class="box"><img src="../img/3.jpg"/></div>
  <div class="box"><img src="../img/4.jpg"/></div>
  <div class="box"><img src="../img/5.jpg"/></div>
  <div class="box"><img src="../img/6.jpg"/></div>
  <div class="box"><img src="../img/7.jpg"/></div>
  <div class="box"><img src="../img/8.jpg"/></div>
  <div class="box"><img src="../img/9.jpg"/></div>
  <div class="box"><img src="../img/10.jpg"/></div>
  <div class="box"><img src="../img/11.jpg"/></div>
  <div class="box"><img src="../img/12.jpg"/></div>
  <div class="box"><img src="../img/13.jpg"/></div>
  <div class="box"><img src="../img/14.jpg"/></div>
  <div class="box"><img src="../img/15.jpg"/></div>
  <div class="box"><img src="../img/16.jpg"/></div>
 </div>
 <script type="text/javascript">
  var boxsHeight = []; //盒子高度存储数组
  var boxWidth = 230, boxHeight = 230;
  window.onload = function(){
   var boxs = document.getElementsByClassName('box');
   var cols = Math.floor(1200.0/boxWidth); //最多几列
   //offsetWidth: 包括元素的内容宽度+padding+border宽度
   //存储第一行的每个盒子的高度到数组里面
   for (var i = 0; i < cols; i++){
    var obj = boxs[i]; //元素节点
    if (i < cols){
     boxsHeight.push(obj.offsetHeight);
    }
   }
   updateBoxFrame(cols); //从第二行开始更新元素的位置
   window.onscroll = pageScroll; //设置页面滚动监听函数
   pageScroll(); //先调用一次
  }
  //获取数组中最小值的索引
  function getMinHeightIndex(arr){
   var minHeight = Math.min.apply(null, arr);
   for (var i = 0; i < arr.length; i++){
    if (arr[i] == minHeight){
     return i;
    }
   }
  }
  //监听页面滚动
  function pageScroll(){
   var parentEle = document.getElementsByClassName('container')[0];
   var subEleCount = parentEle.childElementCount; //子元素个数
   var lastBox = parentEle.lastElementChild; //最后一个元素
   //判断是否滚动到底部
   var doc = document.documentElement||document.body;
   console.log('滚动监听', doc.scrollTop+",", lastBox.offsetTop+", " + doc.clientHeight);
   if (doc.scrollTop+doc.clientHeight > lastBox.offsetTop){
    //表示该新添加元素了
    addBox();
    //更新新添加元素的位置
    updateBoxFrame(subEleCount);
   }
  }
  //新添加子元素
  function addBox(){
   var parentEle = document.getElementsByClassName('container')[0];
   var arr = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16];
   for (var i = 0; i < arr.length; i++){
    var index = parseInt(Math.random()*100%arr.length);
    var imgNum = arr[index];
    var div = document.createElement('div');
    div.setAttribute('class', 'box');
    div.innerHTML = '<img src="../img/' + imgNum + '.jpg"/>'
    parentEle.appendChild(div);
    arr.splice(index, 1)
   }
  }
  //更新新添加元素的位置
  function updateBoxFrame(startIndex){
   var boxs = document.getElementsByClassName('box');
   for (var i = startIndex; i < boxs.length; i++){
    var obj = boxs[i];
    //获取数组中最小高度的索引
    var minHeightIndex = getMinHeightIndex(boxsHeight);
//     console.log(boxsHeight);
//     console.log(minHeightIndex + ", " +boxsHeight[minHeightIndex]);
    var boxTop = boxsHeight[minHeightIndex] + 20;
    var boxLeft = minHeightIndex * boxWidth;
    console.log(i + ', boxTop: ' + boxTop + ", boxLeft: " + boxLeft);
    //设置元素的定位样式
    obj.style = 'position: absolute; top:' + boxTop + "px;left:" + boxLeft+"px";
    boxsHeight[minHeightIndex] = boxTop + obj.offsetHeight;
   }
  }
 </script>
</body>
</html>

　　2、小程序实现瀑布流，大致流程差不多。只不过小程序的图片的宽高度的获取没有web页面那么方便。

大概实现过程：1）、获取图片数据，页面渲染；

　　　　　　2）、给图片绑定加载load事件，存储每个图片的宽高度；

　　　　　　3）、计算每个图片的定位，重新渲染

先看小程序的效果图（瀑布流+无限循环加载）：

wxml页面代码：

<scroll-view class='main' scroll-y='true' style="height:{{windowHeight}}px" bindscrolltolower='loadMoreImages'>
 <image wx:for='{{dataList}}' wx:key='item' src='{{item.src}}' style='position: absolute; top: {{item.top}}px; left: {{item.left}}px; width: {{imgWidth}}px; height: {{item.height}}px' bindload='loadImage' data-index='{{index}}' bindtap='previewImg'/>
</scroll-view>

js页面代码：

// pages/discover/waterfall_flow/waterfall_flow.js
Page({
 /**
 * 页面的初始数据
 */
 data: {
 dataList: [], //数据源
 windowWidth: 0, //页面视图宽度
 windowHeight: 0, //视图高度
 imgMargin: 6, //图片边距: 单位px
 imgWidth: 0, //图片宽度: 单位px
 topArr: [0, 0], //存储每列的累积top
 },
 /**
 * 生命周期函数--监听页面加载
 */
 onLoad: function (options) {
 wx.showLoading({
  title: '加载中...',
 })
 var that = this;
 //获取页面宽高度
 wx.getSystemInfo({
  success: function (res) {
  console.log(res)
  var windowWidth = res.windowWidth;
  var imgMargin = that.data.imgMargin;
  //两列，每列的图片宽度
  var imgWidth = (windowWidth - imgMargin * 3) / 2;
  that.setData({
   windowWidth: windowWidth,
   windowHeight: res.windowHeight,
   imgWidth: imgWidth
  }, function () {
   that.loadMoreImages(); //初始化数据
  });
  },
 })
 },
 //加载图片
 loadImage: function (e) {
 var index = e.currentTarget.dataset.index; //图片所在索引
 var imgW = e.detail.width, imgH = e.detail.height; //图片实际宽度和高度
 var imgWidth = this.data.imgWidth; //图片宽度
 var imgScaleH = imgWidth / imgW * imgH; //计算图片应该显示的高度
 var dataList = this.data.dataList;
 var margin = this.data.imgMargin; //图片间距
 //第一列的累积top，和第二列的累积top
 var firtColH = this.data.topArr[0], secondColH = this.data.topArr[1];
 var obj = dataList[index];
 obj.height = imgScaleH;
 if (firtColH < secondColH) { //表示新图片应该放到第一列
  obj.left = margin;
  obj.top = firtColH + margin;
  firtColH += margin + obj.height;
 }
 else { //放到第二列
  obj.left = margin * 2 + imgWidth;
  obj.top = secondColH + margin;
  secondColH += margin + obj.height;
 }
 this.setData({
  dataList: dataList,
  topArr: [firtColH, secondColH],
 });
 },
 //加载更多图片
 loadMoreImages: function () {
 var imgs = [
  'https://ss1.bdstatic.com/70cFuXSh_Q1YnxGkpoWK1HF6hhy/it/u=1409185525,4059560780&fm=26&gp=0.jpg',
  'https://ss3.bdstatic.com/70cFv8Sh_Q1YnxGkpoWK1HF6hhy/it/u=4076355782,2436939971&fm=15&gp=0.jpg',
  'https://ss1.bdstatic.com/70cFuXSh_Q1YnxGkpoWK1HF6hhy/it/u=777075993,2126273204&fm=11&gp=0.jpg',
  'https://ss2.bdstatic.com/70cFvnSh_Q1YnxGkpoWK1HF6hhy/it/u=57777155,3251523579&fm=11&gp=0.jpg',
  'https://ss3.bdstatic.com/70cFv8Sh_Q1YnxGkpoWK1HF6hhy/it/u=3825727093,2830650732&fm=11&gp=0.jpg',
  'https://ss2.bdstatic.com/70cFvnSh_Q1YnxGkpoWK1HF6hhy/it/u=2379065095,654347953&fm=26&gp=0.jpg',
  'https://ss1.bdstatic.com/70cFuXSh_Q1YnxGkpoWK1HF6hhy/it/u=2749679283,2472217536&fm=11&gp=0.jpg',
  'https://ss3.bdstatic.com/70cFv8Sh_Q1YnxGkpoWK1HF6hhy/it/u=677128138,409184861&fm=11&gp=0.jpg',
  'https://ss0.bdstatic.com/70cFvHSh_Q1YnxGkpoWK1HF6hhy/it/u=1884091074,3049103326&fm=26&gp=0.jpg',
  'https://ss1.bdstatic.com/70cFuXSh_Q1YnxGkpoWK1HF6hhy/it/u=1600363417,3661952978&fm=11&gp=0.jpg',
  'https://ss2.bdstatic.com/70cFvnSh_Q1YnxGkpoWK1HF6hhy/it/u=2069544162,3090555174&fm=11&gp=0.jpg',
  'https://ss0.bdstatic.com/70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=3328655038,3143543956&fm=26&gp=0.jpg',
  'https://ss1.bdstatic.com/70cFvXSh_Q1YnxGkpoWK1HF6hhy/it/u=3953624046,2332872335&fm=26&gp=0.jpg',
  'https://ss0.bdstatic.com/70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=717009955,687560133&fm=26&gp=0.jpg',
  'https://ss1.bdstatic.com/70cFvXSh_Q1YnxGkpoWK1HF6hhy/it/u=4243037288,2388509769&fm=26&gp=0.jpg',
  'https://ss0.bdstatic.com/70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=2644451528,4180971732&fm=26&gp=0.jpg',
  'https://ss0.bdstatic.com/70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=2658655215,924706045&fm=26&gp=0.jpg',
  'https://ss1.bdstatic.com/70cFvXSh_Q1YnxGkpoWK1HF6hhy/it/u=400545645,1325440240&fm=26&gp=0.jpg',
  'https://ss0.bdstatic.com/70cFvHSh_Q1YnxGkpoWK1HF6hhy/it/u=2735743532,3162562682&fm=11&gp=0.jpg',
  'https://ss1.bdstatic.com/70cFvXSh_Q1YnxGkpoWK1HF6hhy/it/u=2357555025,1781222560&fm=26&gp=0.jpg',
  'https://ss1.bdstatic.com/70cFvXSh_Q1YnxGkpoWK1HF6hhy/it/u=1604156508,3282489713&fm=26&gp=0.jpg',
  'https://ss1.bdstatic.com/70cFuXSh_Q1YnxGkpoWK1HF6hhy/it/u=380663325,2271064034&fm=26&gp=0.jpg',
  'https://ss0.bdstatic.com/70cFvHSh_Q1YnxGkpoWK1HF6hhy/it/u=174537541,3462862985&fm=26&gp=0.jpg',
  'https://ss0.bdstatic.com/70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=1752649241,364583051&fm=26&gp=0.jpg',
  'https://ss1.bdstatic.com/70cFuXSh_Q1YnxGkpoWK1HF6hhy/it/u=2890516059,4166188770&fm=27&gp=0.jpg',
  'https://ss2.bdstatic.com/70cFvnSh_Q1YnxGkpoWK1HF6hhy/it/u=2435144503,200941795&fm=11&gp=0.jpg',
  'https://ss0.bdstatic.com/70cFvHSh_Q1YnxGkpoWK1HF6hhy/it/u=877833827,2847590581&fm=26&gp=0.jpg',
  'https://ss3.bdstatic.com/70cFv8Sh_Q1YnxGkpoWK1HF6hhy/it/u=894452177,2810600152&fm=11&gp=0.jpg',
  'https://ss2.bdstatic.com/70cFvnSh_Q1YnxGkpoWK1HF6hhy/it/u=4053642431,248486335&fm=27&gp=0.jpg',
  'https://ss1.bdstatic.com/70cFvXSh_Q1YnxGkpoWK1HF6hhy/it/u=2914607659,905736210&fm=11&gp=0.jpg',
  'https://ss1.bdstatic.com/70cFvXSh_Q1YnxGkpoWK1HF6hhy/it/u=1629456501,1514429218&fm=26&gp=0.jpg',
 ];
 var tmpArr = [];
 for (let i = 0; i < 22; i++) {
  var index = parseInt(Math.random() * 100) % imgs.length;
  var obj = {
  src: imgs[index],
  height: 0,
  top: 0,
  left: 0,
  }
  tmpArr.push(obj);
  imgs.splice(index, 1);
 }
 var dataList = this.data.dataList.concat(tmpArr)
 this.setData({ dataList: dataList }, function(){
  wx.hideLoading()
 });
 },
 /**预览图片 */
 previewImg: function (e) {
 var index = e.currentTarget.dataset.index;
 var dataList = this.data.dataList;
 var currentSrc = dataList[index].src;
 // var srcArr = dataList.map(function (item) {
 // return item.src;
 // });
 wx.previewImage({
  urls: [currentSrc],
 })
 },
})

wxss页面代码：

.main{ width: 100%; height: 100%; position: relative; }
.main image {
 box-shadow: 0 0 10rpx red; border-radius: 8rpx;
}
 

DEMO下载：https://github.com/xiaotanit/Tan_HtmlDemo

web瀑布流页面地址：https://github.com/xiaotanit/Tan_HtmlDemo/blob/master/JS/%E7%80%91%E5%B8%83%E6%B5%81_%E5%B7%A6%E6%B5%AE%E5%8A%A8.html

小程序瀑布流页面地址：https://github.com/xiaotanit/Tan_HtmlDemo/tree/master/wxMini/pages/discover/waterfall_flow

总结

您可能感兴趣的文章:

相关文章