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web页面和微信小程序页面实现瀑布流效果

程序员文章站 2022-06-19 18:17:49
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...

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):

web页面和微信小程序页面实现瀑布流效果

 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):

web页面和微信小程序页面实现瀑布流效果

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

以上所述是小编给大家介绍的web页面和微信小程序页面实现瀑布流效果 ,希望对大家有所帮助