組件-小程式-瀑布流布局 / 資料懶加載功能

效果圖

簡介

可替換圖片瀑布流懶加載 / 視頻瀑布流懶加載等等，更改 wxml 即可，

瀑布流布局 / 資料懶加載功能，絲滑的滑動體驗，

wxss

.img_item {
  width: 48%;
  margin: 1%;
  display: inline-block;
  vertical-align: top;
}

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">
  <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>

js

let col1H = 0;
let col2H = 0;

Page({

    data: {
        scrollH: 0,
        imgWidth: 0,
        loadingCount: 0,
        images: [],
        col1: [],
        col2: []
    },

    onl oad: 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
                });

                this.loadImages();
            }
        })
    },

    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;  //圖片設定的寬度
        let scale = imgWidth / oImgW;        //比例計算
        let imgHeight = oImgH * scale;      //自適應高度

        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;

        if (col1H <= col2H) {
            col1H += imgHeight;
            col1.push(imageObj);
        } else {
            col2H += imgHeight;
            col2.push(imageObj);
        }

        let data = {
            loadingCount: loadingCount,
            col1: col1,
            col2: col2
        };

        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 }
        ];

        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
        });
    }

})