FB 与 React Native 集成时出错

Question

I am trying to integrate FB with my React Native app. I was successfully able to get a login message displayed when I tried the below code for the first time but since then I am getting this message "Facebook Login Error: Alert is not defined".

I took this code from FB developers page and followed the instructions but looks like I am missing something.

I'll Appreciate any pointers

import React from 'react';
import styles from '../styles'
import {connect} from 'react-redux';
import {login} from '../redux/actions'
import * as Facebook from 'expo-facebook';

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

class Home extends React.Component {
  state = {}

  componentWillMount() {
    this.props.dispatch(login("Whats Upp"))
    this.login()
  }

  login = async () => {
    try {
      await Facebook.initializeAsync({
        appId: '1742056282625463',
      });
      const {
        type,
        token,
        expirationDate,
        permissions,
        declinedPermissions,
      } = await Facebook.logInWithReadPermissionsAsync({
        permissions: ['public_profile'],
      });
      if (type === 'success') {
        // Get the user's name using Facebook's Graph API
        const response = await fetch(`https://graph.facebook.com/me?access_token=${token}`);
        Alert.alert('Logged in!', `Hi ${(await response.json()).name}!`);
      } else {
        // type === 'cancel'
      }
    } catch ({ message }) {
      alert(`Facebook Login Error: ${message}`);
    }
  }


  render() {
    return (
      <View>
        <Text>{this.props.user}</Text>
      </View>
    )
  }
}

function mapStateToProps(state) {
  return {
    user: state.user
  };
}
export default connect(mapStateToProps)(Home);

Answer 1

Try to import the Alert from the react-native:

import { 
  Text, 
  View,
  Alert
} from 'react-native';