reactjs - 当我关闭互联网连接时，它没有显示来自 NetInfo.isConnect 函数的错误值

Question

当我从真实设备上关闭互联网连接时，它没有检测到我处于离线状态，但是当再次上线时，它会将值返回为 true。

import React from 'react';
import {
  SafeAreaView,
  StyleSheet,
  View,
  Text,
  StatusBar,
  Image,
  TouchableOpacity,
  FlatList,
  NetInfo
} from 'react-native';

export default class App extends React.Component {
    componentDidMount() {
        NetInfo.isConnected.addEventListener('connectionChange',
        this.handleConnectivityChange);  
    }

    componentWillUnmount() {
        NetInfo.isConnected.removeEventListener('connectionChange', 
        this.handleConnectivityChange);
    }
    handleConnectivityChange = (isConnected) => {
        console.log(isConnected ? 'connected':'not connected')
    }

到目前为止，我没有在这里提到 render()。

Answer 1

使用 React Native Community's NetInfo 因为 RN's version is deprecated .

RNC 版本仅在添加监听器时接受回调。

它应该是:

import NetInfo from "@react-native-community/netinfo";

export default class App extends React.Component {

  constructor(props) {
    super(props)
    this.unsubscribe = null
  }

  componentDidMount() {
    this.unsubscribe = NetInfo.addEventListener(
      this.handleConnectivityChange
    );
  }

  componentWillUnmount() {
    this.unsubscribe();
  }

  handleConnectivityChange = (state) => {
    console.log(state.isConnected ? 'connected': 'not connected')
  }

  render() {...}
}