react-native-waterflow-list-expand

react-native-waterflow-list ( 瀑布流列表 )

基于 RN0.60.5, Typescript3.7.4, React Hooks 实现

一个使用 FlatList 嵌套实现的瀑布流插件 , 允许传入高度未知的 renderItem. 插件内部使用 onLayout 获取每一个 renderItem 高度, 并插入列表后.

ScreenShots

Getting started

$ npm install react-native-waterflow-list --save

or

$ yarn add react-native-waterflow-list

mehods

• clear : 清空渲染列表, 一般用于下拉刷新获取到数据化,清空之前的数据

options

• data: T[] : 列表数据, 数据类型必须为 Object
• numColumns: number : 列数
• keyForItem: (item: T) => string : 用以检测是否以渲染该数据
• heightForItem: (item: T) => number : 如 renderItem 高度已知,则传入以提高性能和加载速度
• asyncHeightForItem: (item: T) => Promise(number): 如item的高度为异步获取的,则通过该函数返回item的真实高度
• renderItem: { item, index }: { item: T, index: number }) => JSX.Element
• onEndReached?: () => Promise<any> | any : 上拉加载, 若传入 Promise 对象, 则须等待 Promise 事件回调后方能再次触发此事件. 若其他则不作处理
• columnsFlatListProps?: FlatListProps : 外层 FlatList 参数
• columnFlatListProps?: FlatListProps : 列 FlatList 参数

Usage Example

import * as React from 'react';
import { Dimensions, Image, RefreshControl, Text, View } from 'react-native';
import { IColumnsHandles } from 'react-native-waterflow-list/src/Columns';
import WaterFlow from 'react-native-waterflow-list/src/';

const width = (Dimensions.get('screen').width - 30) / 2;

const getItemData = (() => {
  let id = 0;
  return () => {
    id++;
    const height = Math.ceil(Math.random() * 1000);
    return {
      id,
      text: Math.random(),
      image_path: `https://picsum.photos/${width}/${height}/?random`,
      height,
      width,
    };
  };
})();

const sleep = (ms: number) => {
  return new Promise(resolve => setTimeout(resolve, ms));
};

const itemDataFactory = () =>
  Array(10)
    .fill('')
    .map(() => getItemData());

interface IItem {
  id: number
  [index: string]: any
}

export default () => {
  const [data, setData] = React.useState<IItem[]>([]);
  const [loading, setLoading] = React.useState(false)

  const WaterFlowRef = React.useRef<IColumnsHandles>()
  const onLoadMore = React.useCallback(async () => {
    setLoading(true)
    await sleep(1000);
    setLoading(false)
    return setData(data.concat(itemDataFactory()));
  }, [data]);
  const loadData = React.useCallback(async () => {
    await sleep(1000);
    return setData(itemDataFactory());
  }, [data])

  React.useEffect(() => {
    setData(itemDataFactory());
  }, []);

  return (
    <WaterFlow
      ref={WaterFlowRef}
      data={data}
      keyForItem={item => item.id}
      numColumns={2}
      onEndReached={onLoadMore}
      //自定义滚动监听(需要的话)
      onScroll={(e) => {console.log(e)}}
      /** 允许 heightForItem 为异步函数 */
      // asyncHeightForItem={async item => {
      //   let height = 0
      //   try {
      //     height = await (new Promise<number>((resolve, reject) => {
      //       Image.getSize(item.image_path, (_, imageHeight) => {
      //         resolve(imageHeight)
      //       }, reject)
      //     }))
      //   } catch (err) { console.log({ err }); }
      //   return height;
      // }}
      /** 如果高度已知则传此方法 */
      // heightForItem={item => {
      //   return item.height;
      // }}
      columnFlatListProps={{
        style: { marginHorizontal: 5, },
      }}
      columnsFlatListProps={{
        ListHeaderComponent: () => <View><Text>Hello</Text></View>,
        refreshControl: <RefreshControl
          style={{ zIndex: 10 }}
          refreshing={loading}
          onRefresh={() => {
            WaterFlowRef.current?.clear()
            loadData()
          }}
          tintColor={'gray'}
        />
        ,
        style: { marginHorizontal: 10, },
      }}
      renderItem={({ item, index }) => {
        return renderItem(item);
      }}
    />
  );
};