React-Native Invariant Violation：元素类型无效 [英] React-Native Invariant Violation: Element type is invalid

问题描述

当我要在我的iPhone Expo上运行我的本机应用程序时，此错误显示在红色背景区域。

When I going to run my react native app on my iPhone Expo this error displayed in red background area.

不变违规：元素type无效：期望一个字符串（对于内置组件）
或类/函数（对于复合组件）但得到：object。您
可能忘记从其定义的文件中导出您的组件。

Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: object. You likely forgot to export your component from the file it's defined in.

这是'内部的App.js' src / components /'folder

this is the App.js inside the 'src/components/' folder

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


export default class App extends Component {
  render() {
    return (
    	<View>
      		<Text>Hello</Text>
      	</View>
    );
  }
}

这是react-native中的主要App.js app文件夹。

This is the main App.js in react-native app folder.

import App from './src/components/App';

我使用expo app运行此代码。如何解决此错误？

I used expo app for run this code. How can I solve this error?

推荐答案

Expo希望您从 /App.js导出组件。但是现在你只导入 /App.js 。世博会没有收到任何组成部分。您需要导出导入的组件，如下所示：

Expo expects you to export a component from /App.js. But right now you are only importing into /App.js. Expo is not receiving any component to render. You need to export the component you imported like this:

export default App;

旁注：仅在必要时使用类组件。

On side note: Use a class component only if you must.

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