react-native下拉刷新组件react-native-flatlist-pull

完成拉下拉刷新的功能后，老板要求下拉刷新要能自定义。于是到网上找了找，发现了react-native-pull这个开源库。但是这个库本身已经很久没更新，里面使用的还是被淘汰的listView，于是我到源码看了看，把列表替换成了flatList，顺便修复了几个bug。

github地址：react-native-flatlist-pull

react-native-flatlist-pull是一个基于FlatList,支持Android和iOS的下拉刷新列表组件。是在另一个项目react-native-pull的基础上进行修改而成。主要将原项目中已经过时的ListView替换成较新的FlatList，同时去掉了原项目中存在BUG的PullView。

PullList 使用

1. 使用npm：npm install react-native-flatlist-pull@latest --save
   使用yarn：yarn add react-native-flatlist-pull
2. 编写代码:

  import {PullList} from 'react-native-pull';

  onPullRelease(resolve) {
    //do something
    setTimeout(() => {
          resolve();
      }, 3000);
  }
  
  <PullList
    onPullRelease={this.onPullRelease}
    // topIndicatorRender={this.topIndicatorRender}
    topIndicatorHeight={60}
    isRefreshing={this.state.isRefreshing}
    
    {...and some FlatList Props}
  />

3. 完整示例代码:example

更多配置项

PullList 下拉效果属性

• style: 设置组件样式，比如可以设置width/height/backgroudColor等
• onPulling: 处于pulling状态时执行的方法
• onPullOk: 处于onPullOk状态时执行的方法
• onPullRelease: 处于pullrelease状态时执行的方法
• topIndicatorRender: 顶部刷新指示组件的渲染方法, 接受4个参数: ispulling, ispullok, ispullrelease，gesturePosition，你可以使用gesturePosition定义动画头部.
• topIndicatorHeight: 顶部刷新指示组件的高度, 若定义了topIndicatorRender则同时需要此属性
• isPullEnd: 是否已经下拉结束，若为true则隐藏顶部刷新指示组件，非必须
• isRefreshing: 标示下拉刷新状态的属性，同react-native官网FlatList中的属性refreshing作用类似。为true显示头部刷新指示器，为false则隐藏头部刷新指示器

PullList 上拉加载更多，可直接使用官网FlatList的属性onEndReached与onEndReachedThreshold进行实现，详情请见Example

完整demo代码示例：

import React, { Component } from 'react';
import {
Text,
View,
ActivityIndicator,
} from 'react-native';

import {PullList} from 'react-native-flatlist-pull';

export default class extends Component {

   constructor(props) {
     super(props);
     this.state = {
       data: [0],
       isRefreshing:false,
       isLoadMore:false
     };
     this.loadMore = this.loadMore.bind(this);
     this.topIndicatorRender = this.topIndicatorRender.bind(this);
     this.onPullRelease=this.onPullRelease.bind(this);
   }
  
   componentDidMount() {
     this.requestData(10);
   }
  
   //自定义下拉刷新指示器
   topIndicatorRender(pulling, pullok, pullrelease) {
     const hide = {position: 'absolute', left: 10000};
     const show = {position: 'relative', left: 0};
     setTimeout(() => {
       if (pulling) {
         this.txtPulling && this.txtPulling.setNativeProps({style: show});
         this.txtPullok && this.txtPullok.setNativeProps({style: hide});
         this.txtPullrelease && this.txtPullrelease.setNativeProps({style: hide});
       } else if (pullok) {
         this.txtPulling && this.txtPulling.setNativeProps({style: hide});
         this.txtPullok && this.txtPullok.setNativeProps({style: show});
         this.txtPullrelease && this.txtPullrelease.setNativeProps({style: hide});
       } else if (pullrelease) {
         this.txtPulling && this.txtPulling.setNativeProps({style: hide});
         this.txtPullok && this.txtPullok.setNativeProps({style: hide});
         this.txtPullrelease && this.txtPullrelease.setNativeProps({style: show});
       }
     }, 1);
     return (
       <View style={{flexDirection: 'row', justifyContent: 'center', alignItems: 'center', height: 60,zIndex:1}}>
         <ActivityIndicator size="small" color="red" />
         <View ref={(c) => {this.txtPulling = c;}}>
           <Text>继续下拉刷新...</Text>
         </View>
         <View ref={(c) => {this.txtPullok = c;}}>
           <Text>松开刷新......</Text>
         </View>
         <View ref={(c) => {this.txtPullrelease = c;}}>
           <Text>刷新中......</Text>
         </View>
       </View>
     );
   }
  
   render() {
     return (
       <PullList
         //FlatList基本属性
         data={this.state.data}
         renderItem={({item,index})=>this.renderItem(item,index)}
         keyExtractor={(item, index) => item.toString()}
  
         //FlatList上拉加载更多
         ListFooterComponent={()=>this.ListFooterComponent()}
         onEndReached={()=>this.loadMore()}
         onEndReachedThreshold={0.1}
  
         //PullList下拉刷新
         onPullRelease={this.onPullRelease}
         topIndicatorRender={this.topIndicatorRender}
         topIndicatorHeight={60}
         //控制下拉刷新状态的属性，为true时显示头部刷新组件，为false则隐藏
         isRefreshing={this.state.isRefreshing}
       />
     );
   }
  
   onPullRelease(resolve) {
     this.setState({isRefreshing:true});
     //do something
     setTimeout(() => {
       //真实情况下，应在请求网络数据后的回调中修改isRefreshing
       this.setState({isRefreshing:false})
     }, 2000);
   }
  
   renderItem(item,index) {
     return (
       <View style={{height: 100, backgroundColor: 'white', alignItems: 'center', justifyContent: 'center'}}>
         <Text style={{fontSize:30}}>{item}</Text>
       </View>
     );
   }
  
   ListFooterComponent=()=>{
     const {isLoadMore}=this.state;
     if(isLoadMore) {
       return (
         <View style={{ height: px2dp(80), alignItems: 'center', justifyContent: 'center', flexDirection: 'row' }}>
           <ActivityIndicator size="small" color="red"/>
           <Text style={{ fontSize: 25, marginLeft: 5 }}>{'正在加载中……'}</Text>
         </View>
       )
     }else return <View/>
   };
  
   loadMore=()=>{
     if(!this.state.isLoadMore) {
       this.setState({ isLoadMore: true });
       //do something
       //真实情况下，应在请求网络数据后的回调中修改isLoadMore
       setTimeout(() => {
         this.requestData(3);
         this.setState({ isLoadMore: false })
       }, 3000);
     }
   };
  
   requestData=(dataLength)=>{
     let currentLength=this.state.data.length;
     for(let i=currentLength;i<currentLength+dataLength;i++) {
       this.state.data.push(i)
     }
   }
}