react本机中的回退字体

import { AppLoading } from 'expo';
import * as Font from 'expo-font';

export default class App extends React.Component {
  state = {
    fontLoaded: false,
  };

  async componentDidMount() {
    await Font.loadAsync({
      'custom-font': require('./path/to/font.ttf'),
    });

    this.setState({ fontLoaded: true });
  }

  render() {
    if (!this.state.fontLoaded) {
      return <AppLoading />;
    }

    return (
      // 应用的其他组件和内容
    );
  }
}

import React from 'react';
import { Text, StyleSheet } from 'react-native';

const styles = StyleSheet.create({
  text: {
    fontFamily: 'custom-font, fallback-font',
  },
});

const MyComponent = () => {
  return <Text style={styles.text}>Hello World</Text>;
};