（React Native）反应本地Redux和keyExtractor中的问题

Question

为什么我的文本无法在我的App.js中呈现，而只是呈现Card部分？我认为我在keyExtractor上有问题，但我还不了解

import React, { Component} from 'react';
import { connect } from 'react-redux';
import { FlatList } from 'react-native';
import ListItem from './ListItem';

class LibraryList extends Component {
    renderItem(library) {
        return <ListItem library={library} />;
    }

    render() {
        return (
            <FlatList 
                data={this.props.libraries}
                renderItem={this.renderItem}
                keyExtractor={(library) => library.id.toString()}
            />
        );      
    }
}

const mapStateToProps = state => {
    return { libraries: state.libraries }; 
};

export default connect(mapStateToProps)(LibraryList);