Question

我将react-native的版本更新为0.59，现在出现红色屏幕，显示以下消息：

不变违规：元素类型无效：预期为字符串（对于内置组件）或类/函数（对于复合组件），但得到：未定义。您可能忘记了从定义文件中导出组件，或者可能混淆了默认导入和命名导入。

在更新之前可以正常工作。我需要更改代码的内容：

import { Platform, View, StatusBar } from 'react-native';

//import { Constants, Notifications } from  'expo-constants';
import Constants from 'expo-constants';
import { handleNotification } from './helpers/notifications';

import CYPTUStyles from './config/styles';
import { connect, getState } from './store';
import * as NavigationService from './navigators/navigationService';
import CreateRootSwitchNavigator from './navigators/AppNavigator';

const LatoRegular = require('./assets/fonts/Lato-Regular.ttf');
const icomoon = require('../resources/fonts/icomoon.ttf');
const HandycheeraRegular = require('./assets/fonts/Handycheera-Regular.otf');
const SpaceMonoRegular = require('./assets/fonts/SpaceMono-Regular.ttf');

class Root extends React.Component {
    constructor(props) {
        super(props);

        this.state = {
            fontsAreLoaded: false
        };
    }

    componentWillMount() {
        this.props.actions.recoverToken();
        this.props.actions.getAccountDetails();
        this.loadFonts();
        console.disableYellowBox = true;

        //this.notificationSubscription = Notifications.addListener(handleNotification);
    }

    componentWillUnmount() {
        // if (this.notificationSubscription) {
        //     this.notificationSubscription.remove();
        // }
    }

    async loadFonts() {
        await Expo.Font.loadAsync({
            Lato_Regular: LatoRegular,
            icomoon: icomoon,
            Handycheera_Regular: HandycheeraRegular,
            SpaceMono_Regular: SpaceMonoRegular
        });
        this.setState({ fontsAreLoaded: true });
    }

    render() {
        if (!this.state.fontsAreLoaded || !this.props.recoverTokenDone) {
            return <Expo.AppLoading />;
        }

        const RootNavigator = CreateRootSwitchNavigator(getState().isLoggedIn);

        return (
            <View style={{ flex: 1 }}>
                {Platform.OS === 'ios' ? (
                    <View>
                        <StatusBar barStyle="light-content" />
                        <View
                            style={{
                                backgroundColor: CYPTUStyles.MadisonDark,
                                height: Constants.statusBarHeight
                            }}
                        />
                    </View>
                ) : null}
                <RootNavigator
                    ref={(navigatorRef) => {
                        NavigationService.setNavigator(navigatorRef);
                    }}
                />
            </View>
        );
    }
}

export default connect(state => ({
    recoverTokenDone: state.recoverTokenDone
}))(Root);

photo: the error on my device

Answer 1

也请在您的AppNavigator.js文件中显示

react-native 0.59不变违规：元素类型无效：预期为字符串

1 个答案: