微信小程序?qū)崿F(xiàn)頁面下拉刷新和上拉加載功能詳解

更新時間：2018年12月03日 12:07:44 作者：kerryqpw

這篇文章主要介紹了微信小程序?qū)崿F(xiàn)頁面下拉刷新和上拉加載功能,結(jié)合實例形式分析了微信小程序頁面下拉刷新和上拉加載相關(guān)事件監(jiān)聽與功能實現(xiàn)操作技巧,需要的朋友可以參考下

本文實例講述了微信小程序?qū)崿F(xiàn)頁面下拉刷新和上拉加載功能。分享給大家供大家參考，具體如下：

web手機端或App中經(jīng)常會有下拉刷新，上拉加載這些功能。

微信小程序中如何實現(xiàn)下拉刷新，上拉加載的功能。

實現(xiàn)思路：

1.監(jiān)聽界面的下拉刷新事件和上拉加載事件

bindscrolltolower 監(jiān)聽上拉加載
bindscrolltoupper 監(jiān)聽下拉刷新

2.下拉刷新時清空數(shù)據(jù)列表，并重新請求數(shù)據(jù)進(jìn)行界面展示。

3.上拉加載增量請求數(shù)據(jù)，增量增加數(shù)據(jù)列表，增量界面展示

效果圖：

實現(xiàn)代碼：

WaterFall.wxml:

<!--pages/WaterFall/WaterFall.wxml-->
<view style="display:none">
 <image wx:for="{{images}}" wx:key="id" id="{{item.id}}" src="{{item.pic}}" bindload="onImageLoad"></image>
</view>
<scroll-view scroll-y="true" style="height:{{scrollH}}px" bindscrolltolower="loadImages" bindscrolltoupper="PullDownRefresh">
 <view style="width:100%">
  <view class="img_item">
   <view wx:for="{{col1}}" wx:key="id">
    <image src="{{item.pic}}" style="width:100%;height:{{item.height}}px"></image>
   </view>
  </view>
  <view class="img_item">
   <view wx:for="{{col2}}" wx:key="id">
    <image src="{{item.pic}}" style="width:100%;height:{{item.height}}px"></image>
   </view>
  </view>
 </view>
</scroll-view>

WaterFall.js：

let col1H = 0;
let col2H = 0;
Page({
 data: {
  scrollH: 0,
  imgWidth: 0,
  loadingCount: 0,
  images: [],
  col1: [],
  col2: []
 },
 onLoad: function () {
  wx.getSystemInfo({
   success: (res) => {
    let ww = res.windowWidth;
    let wh = res.windowHeight;
    let imgWidth = ww * 0.48;
    let scrollH = wh;
    this.setData({
     scrollH: scrollH,
     imgWidth: imgWidth
    });
    //加載首組圖片
    this.loadImages();
   }
  })
 },
 PullDownRefresh:function(){
  console.log("頁面下拉2");
 },
  onShow: function () {
   console.log("頁面顯示");
 },
 /**
  * 生命周期函數(shù)--監(jiān)聽頁面隱藏
  */
 onHide: function () {
  console.log("頁面隱藏");
 },
 /**
  * 用戶點擊右上角分享
  */
 onShareAppMessage: function () {
  console.log("點擊分享");
 },
 onImageLoad: function (e) {
  let imageId = e.currentTarget.id;
  let oImgW = e.detail.width;     //圖片原始寬度
  let oImgH = e.detail.height;    //圖片原始高度
  let imgWidth = this.data.imgWidth; //圖片設(shè)置的寬度
  let scale = imgWidth / oImgW;    //比例計算
  let imgHeight = oImgH * scale;   //自適應(yīng)高度
  let images = this.data.images;
  let imageObj = null;
  for (let i = 0; i < images.length; i++) {
   let img = images[i];
   if (img.id === imageId) {
    imageObj = img;
    break;
   }
  }
  imageObj.height = imgHeight;
  let loadingCount = this.data.loadingCount - 1;
  let col1 = this.data.col1;
  let col2 = this.data.col2;
  //判斷當(dāng)前圖片添加到左列還是右列
  if (col1H <= col2H) {
   col1H += imgHeight;
   col1.push(imageObj);
  } else {
   col2H += imgHeight;
   col2.push(imageObj);
  }
  let data = {
   loadingCount: loadingCount,
   col1: col1,
   col2: col2
  };
  //當(dāng)前這組圖片已加載完畢，則清空圖片臨時加載區(qū)域的內(nèi)容
  if (!loadingCount) {
   data.images = [];
  }
  this.setData(data);
 },
 loadImages: function () {
  let images = [
   { pic: "../../images/1.png", height: 0 },
   { pic: "../../images/2.png", height: 0 },
   { pic: "../../images/3.png", height: 0 },
   { pic: "../../images/4.png", height: 0 },
   { pic: "../../images/5.png", height: 0 },
   { pic: "../../images/6.png", height: 0 },
   { pic: "../../images/7.png", height: 0 },
   { pic: "../../images/8.png", height: 0 },
   { pic: "../../images/9.png", height: 0 },
   { pic: "../../images/10.png", height: 0 },
   { pic: "../../images/11.png", height: 0 },
   { pic: "../../images/12.png", height: 0 },
   { pic: "../../images/13.png", height: 0 },
   { pic: "../../images/14.png", height: 0 }
  ];
  console.log("dasddasd" + images);
  let baseId = "img-" + (+new Date());
  for (let i = 0; i < images.length; i++) {
   images[i].id = baseId + "-" + i;
  }
  this.setData({
   loadingCount: images.length,
   images: images
  });
 }
})

希望本文所述對大家微信小程序設(shè)計有所幫助。

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