我得到这个错误:
Uncaught Error: Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: object.
这是我的代码:
var React = require('react')
var ReactDOM = require('react-dom')
var Router = require('react-router')
var Route = Router.Route
var Link = Router.Link
var App = React.createClass({
render() {
return (
<div>
<h1>App</h1>
<ul>
<li><Link to="/about">About</Link></li>
</ul>
</div>
)
}
})
var About = require('./components/Home')
ReactDOM.render((
<Router>
<Route path="/" component={App}>
<Route path="about" component={About} />
</Route>
</Router>
), document.body)
我的家。jsx文件:
var React = require('react');
var RaisedButton = require('material-ui/lib/raised-button');
var Home = React.createClass({
render:function() {
return (
<RaisedButton label="Default" />
);
},
});
module.exports = Home;
对我来说，它是app config json的名称。在index.js中，导入是这样的:
import { AppRegistry } from 'react-native'
import App from './app'
import { name as appName } from './app.json'
AppRegistry.registerComponent(appName, () => App)
React Native不区分'。./app '和'./app.json'。不知道为什么。因此，我已经将app.json的名称更改为app.config.json，这已经解决了问题:
import { AppRegistry } from 'react-native'
import App from './app'
import { name as appName } from './app.config.json'
AppRegistry.registerComponent(appName, () => App)
@Balasubramani M救了我。想再加一个来帮助人们。当你把太多的东西粘在一起，对版本漫不经心时，这就是问题所在。我更新了material-ui的一个版本，需要更改
import Card, {CardContent, CardMedia, CardActions } from "@material-ui/core/Card";
:
import Card from '@material-ui/core/Card';
import CardActions from '@material-ui/core/CardActions';
import CardContent from '@material-ui/core/CardContent';
import CardMedia from '@material-ui/core/CardMedia';
假设你的错误是:
未捕获错误:不变量违反:元素类型无效:期望为字符串(对于内置组件)或类/函数，但got: object
你有两个选择:
您的导出文件可以有字默认，如
export default class someNameHere
那么您的导入将需要避免在它周围使用{}。就像在
import somethingHere from someWhereHere
避免使用默认单词。然后你的导出是这样的
export class someNameHere
然后导入必须使用{}。就像
import {somethingHere} from someWhereHere
