似乎不允许我从react本机元素导入FormInput。
我发现了一个错误:
Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, or you might have mixed up
我正在使用react和npm组件包创建一个chrome扩展。我试图在页面上显示一条错误消息。当我触发错误消息组件时,我得到了一个错误。
这是错误:-
Error: Minified React error #130; visit https://reactjs.org/docs/error-decoder.html?invariant=130&args[]=undefined&args[]= for the full message or use the non-minified dev environment for full errors and additional he
import React from 'react';
import ReactDOM from 'react-dom';
import Map from './components/map/container/map';
import App from './App';
import './index.css';
import shell from './shared/utility/shell';
import { render } from 'react-dom'
import
当前行为
使用react-native-tab-view v1.0.0时,出现错误:
Invariant Violation: Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, o
我知道这个问题已经被问了很多次了,但是我读到的解决方案在我的案例中行不通。我的代码非常简单明了:
// Import a library to help create a component
import React from 'react';
import { AppRegistry, Text } from 'react-native';
//Only access text and AppRegistry from React-native lib
//Create a component
const App = () => (
<
试图获得react路由器(v4.0.0)和react热加载程序(3.0.0-beta.6)来很好地运行,但是在浏览器控制台中得到以下错误:
Warning: React.createElement: type is invalid -- expected a string
(for built-in components) or a class/function (for composite
components) but got: undefined. You likely forgot to export your
component from the file it's defi
我正在致力于一个反应本地项目与博览会和纱线,并需要安装一个新的依赖,以获得设备制造商(它是反应-本机设备-信息,如果你想知道)。我成功地安装了它,并在我的代码中实现了它,但是在用expo go打开应用程序时,我看到了一条错误消息。
@React-native-community/react-native-device-info: NativeModule.RNDeviceInfo is null. To fix this issue follow these steps: *useless steps*
在github中,我发现了很多问题来解决这个问题(开发人员回答这个问题不是他的问题,因为它
我试图制作一个简单的动画,在那里我的形象会褪色。
下面的代码我正在导入{useSpring, animated} from 'react-spring'。我创建了简单的useSpring函数logoLoadingScreen。然后,我在图像样式设计中添加了函数,但是没有显示任何动画。
import React from 'react';
import {useSpring, animated} from 'react-spring'
import {View,Text,StyleSheet,Image} from 'react-nativ
我收到一个错误。React.createElement:类型无效--应为字符串(对于内置组件)或类/函数(对于复合组件),但got: undefined
我正在尝试在Index.js中使用导入的riutes
import React from 'react';
import ReactDom from 'react-dom';
import routes from './routes.js';
import { HashRouter as Router, Route, IndexRoute } from 'react-router
我正在学习一个教程来了解React.js是如何工作的。我被困在使用参考资料访问组件的地方。如果有人不介意的话,看看我的代码,告诉我哪里错了。但是这就是我所做的。我有一个通用组件App和html Input标记,用于更新State中的refs。但是,我不知道为什么它还在向undefined展示
import React from 'react';
import ReactDOM from 'react-dom';
class App extends React.Component {
constructor() {
super();
this
所以我尝试redux和react,我一直在模拟器中得到这个错误
Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined.
和
Warning: React.createElement: type is invalid -- expected a string (for built-in components) or a class/function (for composite c
我有点困惑如何使用反应路由器v4。上一次我使用它的时候,我使用了v2,没有什么不同。我试着学习一些教程,但我无法让它开始工作。
我知道这两个错误:
app.bundle.js:358 Warning: React.createElement: type is invalid -- expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from
App.js:
import React from 'react';
import Home from './screens/home';
import Navigator from './routes/drawer';
import Login from './screens/login';
export default class App extends React.Component{
render() {
if (false) {
return (
我有一个React类,我们称它为A。我正在对它运行一个jest测试,但我一直收到
Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: object.
在我正在做的React类中:export class A extends Component ..
在我正在执行的jest测试文件中:import { A } from './A.js'
当我运