微信小程序实现页面下拉刷新和上拉加载功能详解

本文实例讲述了微信小程序实现页面下拉刷新和上拉加载功能。分享给大家供大家参考，具

本文实例讲述了微信小程序实现页面下拉刷新和上拉加载功能。分享给大家供大家参考，具体如下：

web手机端或App中经常会有下拉刷新，上拉加载这些功能。

微信小程序中如何实现下拉刷新，上拉加载的功能。

实现思路：

1.监听界面的下拉刷新事件和上拉加载事件

• bindscrolltolower 监听上拉加载
• bindscrolltoupper 监听下拉刷新

2.下拉刷新时清空数据列表，并重新请求数据进行界面展示。

3.上拉加载增量请求数据，增量增加数据列表，增量界面展示

效果图：

实现代码：

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
 });
 //加载首组图片
 this.loadImages();
 }
 })
 },
 PullDownRefresh:function(){
 console.log("页面下拉2");
 },
 onShow: function () {
 console.log("页面显示");
 },
 /**
 * 生命周期函数--监听页面隐藏
 */
 onHide: function () {
 console.log("页面隐藏");
 },
 /**
 * 用户点击右上角分享
 */
 onShareAppMessage: function () {
 console.log("点击分享");
 },
 onImageLoad: function (e) {
 let imageId = e.currentTarget.id;
 let oImgW = e.detail.width; //图片原始宽度
 let oImgH = e.detail.height; //图片原始高度
 let imgWidth = this.data.imgWidth; //图片设置的宽度
 let scale = imgWidth / oImgW; //比例计算
 let imgHeight = oImgH * scale; //自适应高度
 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;
 //判断当前图片添加到左列还是右列
 if (col1H <= col2H) {
 col1H += imgHeight;
 col1.push(imageObj);
 } else {
 col2H += imgHeight;
 col2.push(imageObj);
 }
 let data = {
 loadingCount: loadingCount,
 col1: col1,
 col2: col2
 };
 //当前这组图片已加载完毕，则清空图片临时加载区域的内容
 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
 });
 }
})

希望本文所述对大家微信小程序设计有所帮助。