React Native：网络信息

网络信息公开在线或者离线信息

reachabilityIOS

异步确定设备是否处于在线状态并且在蜂窝网络。

• None – 设备处于离线状态

• WiFi – 设备处于在线状态，并且通过 WiFi 或者是 iOS 模拟器连接

• Cell – 设备通过网络连接，3G，WiMax，或者 LTE 进行连接

• Unknown – 错误情况，并且网络状态未知

    NetInfo.reachabilityIOS.fetch().done((reach) => {      console.log(Initial:  + reach);
    });    function handleFirstReachabilityChange(reach) {      console.log(First change:  + reach);
      NetInfo.reachabilityIOS.removeEventListener(        change,
        handleFirstReachabilityChange
      );
    }
    NetInfo.reachabilityIOS.addEventListener(      change,
      handleFirstReachabilityChange
    );

连接状态

在所有的平台上都可用。异步获取一个布尔值来确定网络连接。

    NetInfo.isConnected.fetch().done((isConnected) => {      console.log(First, is  + (isConnected ? online : offline));
    });    function handleFirstConnectivityChange(isConnected) {      console.log(Then, is  + (isConnected ? online : offline));
      NetInfo.isConnected.removeEventListener(        change,
        handleFirstConnectivityChange
      );
    }
    NetInfo.isConnected.addEventListener(      change,
      handleFirstConnectivityChange
    );

例子

Edit on GitHub

    use strict;    var React = require(react-native);    var {
      NetInfo,
      Text,
      View
    } = React;    var ReachabilitySubscription = React.createClass({
      getInitialState() {        return {
          reachabilityHistory: [],
        };
      },
      componentDidMount: function() {
        NetInfo.reachabilityIOS.addEventListener(          change,          this._handleReachabilityChange
        );
      },
      componentWillUnmount: function() {
        NetInfo.reachabilityIOS.removeEventListener(          change,          this._handleReachabilityChange
        );
      },
      _handleReachabilityChange: function(reachability) {        var reachabilityHistory = this.state.reachabilityHistory.slice();
        reachabilityHistory.push(reachability);        this.setState({
          reachabilityHistory,
        });
      },
      render() {        return (          <View>
            <Text>{JSON.stringify(this.state.reachabilityHistory)}</Text>
          </View>
        );
      }
    });    var ReachabilityCurrent = React.createClass({
      getInitialState() {        return {
          reachability: null,
        };
      },
      componentDidMount: function() {
        NetInfo.reachabilityIOS.addEventListener(          change,          this._handleReachabilityChange
        );
        NetInfo.reachabilityIOS.fetch().done(
          (reachability) => { this.setState({reachability}); }
        );
      },
      componentWillUnmount: function() {
        NetInfo.reachabilityIOS.removeEventListener(          change,          this._handleReachabilityChange
        );
      },
      _handleReachabilityChange: function(reachability) {        this.setState({
          reachability,
       });
      },
      render() {        return (          <View>
            <Text>{this.state.reachability}</Text>
          </View>
        );
      }
    });    var IsConnected = React.createClass({
      getInitialState() {        return {
          isConnected: null,
        };
      },
      componentDidMount: function() {
        NetInfo.isConnected.addEventListener(          change,          this._handleConnectivityChange
        );
        NetInfo.isConnected.fetch().done(
          (isConnected) => { this.setState({isConnected}); }
        );
      },
      componentWillUnmount: function() {
        NetInfo.isConnected.removeEventListener(          change,          this._handleConnectivityChange
        );
      },
      _handleConnectivityChange: function(isConnected) {        this.setState({
          isConnected,
        });
      },
      render() {        return (          <View>
            <Text>{this.state.isConnected ? Online : Offline}</Text>
          </View>
        );
      }
    });
    exports.title = NetInfo;
    exports.description = Monitor network status;
    exports.examples = [
      {
        title: NetInfo.isConnected,
        description: Asyncronously load and observe connectivity,
        render(): ReactElement { return <IsConnected />; }
      },
      {
        title: NetInfo.reachabilityIOS,
        description: Asyncronously load and observe iOS reachability,
        render(): ReactElement { return <ReachabilityCurrent />; }
      },
      {
        title: NetInfo.reachabilityIOS,
        description: Observed updates to iOS reachability,
        render(): ReactElement { return <ReachabilitySubscription />; }
      },
    ];