React native (已解决)TypeError:undefined不是对象(正在计算';y.Font.isLoaded';)

React native (已解决)TypeError:undefined不是对象(正在计算';y.Font.isLoaded';),react-native,expo,mobile-application,React Native,Expo,Mobile Application,我正在学习handlebarlabs的货币转换器应用程序课程。我正试图通过从@expo/vector icons导入Ionicons,将图标添加到我的ScrollView列表项中 谁能告诉我我做错了什么 以下是我根据课程笔记编写的代码: import React, { Component } from 'react'; import { ScrollView, StatusBar, Platform } from 'react-native'; import { Ionicons } from

我正在学习handlebarlabs的货币转换器应用程序课程。我正试图通过从@expo/vector icons导入Ionicons,将图标添加到我的ScrollView列表项中

谁能告诉我我做错了什么

以下是我根据课程笔记编写的代码:

import React, { Component } from 'react';
import { ScrollView, StatusBar, Platform } from 'react-native';
import { Ionicons } from '@expo/vector-icons';

import { ListItem, Separator } from '../components/List';

const ICON_PREFIX = Platform.OS === 'ios' ? 'ios' : 'md';
const ICON_COLOR = '#868686';
const ICON_SIZE = 23;

class Options extends Component {
    handleThemesPress = () => {
        console.log('Press Themes');
    }

    handleSitePress = () => {
        console.log('Site Press');
    }

    render() {
        return (
            <ScrollView>
                <StatusBar translucent={false} barStyle={"default"} />
                <ListItem 
                    text="Themes"
                    onPress={this.handleThemesPress}
                    customIcon={
                        <Ionicons name={`${ICON_PREFIX}-arrow-forward`} size={ICON_SIZE} color={ICON_COLOR} />
                    }
                />
                <Separator/>
                <ListItem 
                    text="Fixer.io"
                    onPress={this.handleSitePress}
                    customIcon={
                        <Ionicons name={`${ICON_PREFIX}-link`} size={ICON_SIZE} color={ICON_COLOR} />
                    }
                />

                <Separator/>
            </ScrollView>
        );
    }
}

export default Options;
更新:
按照@Oleg的回答,我已经在SDK 35.0.0上了,但之前的更新似乎没有正确完成。重新安装最新的SDK解决了这个问题。谢谢大家!

我使用Ionic示例通过重用您发布的代码创建了零食。 请检查项目中package.json和expo sdk中的版本。

如果您的Expo SDK已过时,请尝试将其更新为最新版本。查看此链接以更新:希望此帮助已在SDK 35上,但重新安装SDK解决了此问题。非常感谢。
TypeError: undefined is not an object (evaluating 'y.Font.isLoaded')
This error is located at:
   in p
   in RCTView
   in RCTView
   in TouchableHighlight
   in f
   in RCTScrollContentView
   in RCTScrollView
   in u
   in l
   in Unknown
   in v
   in RCTView
   in RCTView
   in c