当应用程序未使用或处于后台模式时，React Native 是否具有生命周期为 运行 的功能？

Question

当应用程序未使用或处于后台模式时，React Native 是否具有生命周期为 运行 的函数？

我需要一个函数生命周期，当用户不使用应用程序或应用程序处于后台模式时，react-native 正在运行。我想检查数据库以获取通知 componentDidMount 正在工作，但用户必须打开应用程序并再次关闭它

我需要一个功能或生命周期始终有效

这是我的通知代码：

import React, { Component } from 'react';
import { View, NetInfo, Image, AppState, DeviceEventEmitter } from 'react-native';
import { Container, Text } from 'native-base';
import { RootNavigator } from './src/root';
import { Provider } from 'react-redux';
import { createStore } from 'redux';
import resducers from './src/reducers/index';
import PushController from'./PushController';
import PushNotification from 'react-native-push-notification';
import PushNotificationAndroid from 'react-native-push-notification';

const store = createStore(resducers);

export default class App extends Component<Props> {
  constructor(Props){
    super(Props);
    this.state={
      connection:null,
    }
    this.handleAppStateChange = this.handleAppStateChange.bind(this);
    this.sendNotification = this.sendNotification.bind(this);
  }

  componentDidMount(){
    AppState.addEventListener('change',this.handleAppStateChange);
  }

  componentWillMount(){
    NetInfo.isConnected.addEventListener("connectionChange",this.handleConnectionChange);
    NetInfo.isConnected.fetch().done((isConnected)=>this.setState({connection:isConnected}));

    PushNotificationAndroid.registerNotificationActions(['Accept','Reject','Yes','No']);
    DeviceEventEmitter.addListener('notificationActionReceived', function(e){
      console.log ('notificationActionReceived event received: ' + e);
      const info = JSON.parse(e.dataJSON);
      if (info.action == 'Yes') {
        alert('Accept');
      } else if (info.action == 'No') {
        alert('Reject')
      }
      // Add all the required actions handlers
    });
  }

  componentWillUnMount(){
    NetInfo.isConnected.removeEventListener("connectionChange",this.handleConnectionChange);
    AppState.removeEventListener('change',this.handleAppStateChange);
  }

  handleConnectionChange=(isConnected)=>{
    this.setState({connection:isConnected});
  }

  handleAppStateChange(appState){
    if(appState==='background'){
      PushNotification.localNotificationSchedule({
        message:'Scheduled notification delay message',
        date:new Date(Date.now()+(2000))
      })
    }
  }
  sendNotification(){
    PushNotification.localNotification({
      message:'You Pushed the notification button',
      title:'My Notification Title',
      ongoing:true,
      vibrate:true,
      playSound:true,
      actions:'["Yes","No"]',
      color:'red'
    })
  }

  handeView(){
    if(this.state.connection!==null && this.state.connection){
      return <RootNavigator />
    }else {
      return <View style={{flex:1, alignItems:"center", justifyContent:"center"}}>
         <Image source={require("./images/connection.gif")} style={{height: 150, width: 150, resizeMode : "stretch"}}/>
         <Text style={{ fontFamily:"IRANSans", fontSize:18, textAlign:"center", color:"#b0b5bb" }}>لطفا اتصال اینترنت خود را بررسی کنید ...</Text>
      </View>
    }
  }

  render() {
    return (
      <Provider store={store}>
         <Container>
             {this.handeView()}
             {this.sendNotification()}
         </Container>
      </Provider>
    );
  }
}

Answer 1

正如@dentemm 提到的，这需要在本机代码中 运行 因此您可以尝试使用此模块 https://github.com/jamesisaac/react-native-background-task

注意： 对于通知，我们通常使用外部服务向用户推送通知，例如 Firebase、Amazone SNS 或 Google Cloud Messages，通知将到达用户即使您的应用程序完全关闭，因为 OS 将处理通知并打开您的应用程序，并且 运行 当用户单击它时为您提供一个功能，有关更多详细信息，您可以查看本教程 https://medium.com/differential/how-to-setup-push-notifications-in-react-native-ios-android-30ea0131355e