android上的React Native Webview返回按钮返回

npm install react-native-webview --save

import { WebView } from 'react-native-webview';

import React, { Component } from 'react';
import { WebView, BackHandler, Platform, Alert } from 'react-native';

class MyWebView extends Component {
  componentDidMount() {
    if (Platform.OS === 'android') {
      BackHandler.addEventListener('hardwareBackPress', this.handleBackButton);
    }
  }

  componentWillUnmount() {
    if (Platform.OS === 'android') {
      BackHandler.removeEventListener('hardwareBackPress', this.handleBackButton);
    }
  }

  handleBackButton = () => {
    if (this.webview && this.webview.canGoBack()) {
      this.webview.goBack();
      return true;
    } else {
      Alert.alert(
        '确认退出',
        '确定要退出应用吗？',
        [
          { text: '取消', style: 'cancel' },
          { text: '确定', onPress: () => BackHandler.exitApp() }
        ],
        { cancelable: false }
      );
      return true;
    }
  };

  render() {
    return (
      <WebView
        ref={(ref) => (this.webview = ref)}
        source={{ uri: 'https://example.com' }}
      />
    );
  }
}

export default MyWebView;