在 expo 项目中加载自定义字体时出错 [英] Error while loading custom fonts in expo project
问题描述
我正在尝试在我的 expo 托管项目中加载字体,我已按照 https://docs.expo.io/versions/latest/sdk/font/ 但它向我显示了这个错误"错误:App(...):渲染没有返回任何内容.这通常意味着缺少 return 语句.或者,不渲染任何内容,返回 null."
I am trying to load fonts in my expo managed project, I've followed the example given at https://docs.expo.io/versions/latest/sdk/font/ but it shows me this error "Error: App(...): Nothing was returned from render. This usually means a return statement is missing. Or, to render nothing, return null."
这是我的 App.js 代码
Here's my code for App.js
import React from "react";
import { View } from "react-native";
import { NavigationContainer } from "@react-navigation/native";
import { createStackNavigator } from "@react-navigation/stack";
import { useFonts } from "expo-font";
import { AppLoading } from "expo";
import LoginScreen from "./assets/Screens/LoginScreen";
import RegisterScreen from "./assets/Screens/RegisterScreen";
const Stack = createStackNavigator();
const App = () => {
const [isFontLoaded] = useFonts({
nimbusBold: require("./assets/fonts/NimbusMonoPS-Bold.otf"),
nimbusRegular: require("./assets/fonts/NimbusMonoPS-Regular.otf"),
});
if (!isFontLoaded) {
return AppLoading;
}
return (
<NavigationContainer>
<Stack.Navigator
initialRouteName="Login"
screenOptions={{
headerShown: false,
}}
>
<Stack.Screen name="Login" component={LoginScreen} />
<Stack.Screen name="Register" component={RegisterScreen} />
</Stack.Navigator>
</NavigationContainer>
);
};
export default App;
有谁知道为什么会这样.感谢您宝贵的时间并提前回答.
Does anyone know why is this happening. Thanks for precious time and answer in advance.
推荐答案
首先,运行 npm i expo-font
然后,运行 npm i @expo-google-fonts/open-sans
然后,运行 npm i expo-app-loading
然后在您的项目文件夹中创建一个名为 hooks
的文件,您的 App.js
所在的位置.
Then in your project folder create a file called hooks
where your App.js
is located.
在 hooks
文件夹中创建一个名为 useFonts.js
的文件并在其中粘贴此代码
in hooks
folder create a file called useFonts.js
and inside that paste this code
import * as Font from 'expo-font';
const useFonts = async () => {
await Font.loadAsync({
Montserrat: require('../assets/fonts/Mulish.ttf'),
});
};
export default useFonts;
您的 App.js
应如下所示
import React, { Component, useState } from 'react';
import { StyleSheet, Text, View } from 'react-native';
import { NavigationContainer } from '@react-navigation/native';
import { createStackNavigator } from '@react-navigation/stack';
import AppLoading from 'expo-app-loading'; // This is must
import useFonts from './hooks/useFonts';
import LoginScreen from './assets/screens/LoginScreen';
import RegisterScreen from './assets/screens/RegisterScreen';
const Stack = createStackNavigator();
export default function App(props) {
const [IsReady, SetIsReady] = useState(false);
const LoadFontsAndRestoreToken = async () => {
await useFonts();
};
if (!IsReady) {
return (
<AppLoading
startAsync={LoadFontsAndRestoreToken}
onFinish={() => SetIsReady(true)}
onError={() => {}}
/>
);
}
return (
<NavigationContainer>
<Stack.Navigator
initialRouteName="Login"
screenOptions={{
headerShown: false,
}}>
<Stack.Screen name="Login" component={LoginScreen} />
<Stack.Screen name="Register" component={RegisterScreen} />
</Stack.Navigator>
</NavigationContainer>
);
}
你的 LoginScreen.js
应该是这样的
import React from 'react';
import { View, StyleSheet, Text } from 'react-native';
function LoginScreen(props) {
return (
<View style={styles.container}>
<Text style={{ fontFamily: 'Montserrat', fontSize: 30 }}>
LoginScreen with fontFamily
</Text>
<Text style={{ fontSize: 30 }}>LoginScreen without fontFamily</Text>
</View>
);
}
export default LoginScreen;
const styles = StyleSheet.create({
container: {},
});
这是加载字体的最佳方式,我在所有项目中都这样做.
This is the best way to load fonts and I do it like this in all my projects.
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