Javascript Reactjs未捕获错误:元素类型无效:应为字符串
我得到以下错误: “未捕获错误:元素类型无效:需要字符串(对于内置组件)或类/函数(对于复合组件),但得到:未定义。请检查Javascript Reactjs未捕获错误:元素类型无效:应为字符串,javascript,reactjs,webpack,react-bootstrap,react-dom,Javascript,Reactjs,Webpack,React Bootstrap,React Dom,我得到以下错误: “未捕获错误:元素类型无效:需要字符串(对于内置组件)或类/函数(对于复合组件),但得到:未定义。请检查App的呈现方法。” 我已经检查并加倍检查了我的代码,我无法解决这个问题 有人知道为什么吗?请参阅下面的代码 App.js import React, {Component} from 'react'; import ReactDOM from 'react-dom'; //import ReactD3, {BarChart, LineChart} from 'react-d
App
的呈现方法。”
我已经检查并加倍检查了我的代码,我无法解决这个问题
有人知道为什么吗?请参阅下面的代码
App.js
import React, {Component} from 'react';
import ReactDOM from 'react-dom';
//import ReactD3, {BarChart, LineChart} from 'react-d3-components';
import {MenuList} from './menu/menulist.js';
import {TabList} from './menu/tablist.js';
import {TabContainer, TabContent, TabPane, Nav, Tab, Row, Col} from 'react-bootstrap';
class App extends Component{
constructor(props){
super(props);
}
render(){
console.log("Here 1")
const menunames = [
{id: "first", name: "Tab 1"},
{id: "second", name: "Tab 2"}
];
const plist = [
{id: "first", name: "Content 1"},
{id: "second", name: "Content 2"}
];
console.log("Here 2")
return (
<div className="app">
<Tab.Container id="left-tabs-example">
<Row className="clearfix">
<Col sm={4}>
<MenuList items={menunames} />
</Col>
<Col sm={8}>
<TabList panels={plist} />
</Col>
</Row>
</Tab.Container>
</div>
);
}
}
export default App
import React,{Component}来自'React';
从“react dom”导入react dom;
//从“react-d3-components”导入react3,{BarChart,LineChart};
从“./menu/MenuList.js”导入{MenuList};
从“./menu/TabList.js”导入{TabList};
从'react bootstrap'导入{TabContainer、TabContent、TabPane、Nav、Tab、Row、Col};
类应用程序扩展组件{
建造师(道具){
超级(道具);
}
render(){
console.log(“这里是1”)
常量菜单=[
{id:“first”,name:“Tab 1”},
{id:“second”,name:“Tab 2”}
];
常数plist=[
{id:“first”,name:“Content 1”},
{id:“second”,name:“Content 2”}
];
console.log(“此处为2”)
返回(
);
}
}
导出默认应用程序
menulist.js
import React, {Component} from 'react';
import ReactDOM from 'react-dom';
import {TabContainer, TabContent, TabPane, Nav, NavItem, Tab, Row, Col} from 'react-bootstrap';
class MenuList extends Component{
constructor(props){
super(props);
}
MenuItem({ menuitems }){
return menuitems.map(item => (
<NavItem eventKey={item.id}>
{item.name}
</NavItem>
))
}
render(){
return (
<Nav bsStyle="pills" stacked>
<MenuItem menuitems={this.props.items} />
</Nav>
)
}
}
MenuList.propTypes = {
items: React.PropTypes.array
}
export default MenuList
import React,{Component}来自'React';
从“react dom”导入react dom;
从“react bootstrap”导入{TabContainer、TabContent、TabPane、Nav、NavItem、Tab、Row、Col};
类MenuList扩展了组件{
建造师(道具){
超级(道具);
}
MenuItem({menuitems}){
返回menuitems.map(项=>(
{item.name}
))
}
render(){
返回(
)
}
}
MenuList.propTypes={
项目:React.PropTypes.array
}
导出默认菜单列表
tablist.js
import React, {Component} from 'react';
import ReactDOM from 'react-dom';
import {TabContainer, TabContent, TabPane, Nav, Tab, Row, Col} from 'react-bootstrap';
class TabList extends Component{
constructor(props){
super(props);
}
TabPanel({ pans }){
return pans.map(panel => (
<Tab.Pane eventKey={panel.id}>
{panel.name}
</Tab.Pane>
))
}
render(){
return (
<Tab.Content animation>
this.props.panels.map(panel => (
<Tab.Pane eventKey={panel.id}>
{panel.name}
</Tab.Pane>
)
</Tab.Content>
)
}
}
TabList.propTypes = {
panels: React.PropTypes.array
}
export default TabList
import React,{Component}来自'React';
从“react dom”导入react dom;
从'react bootstrap'导入{TabContainer、TabContent、TabPane、Nav、Tab、Row、Col};
类列表扩展组件{
建造师(道具){
超级(道具);
}
TabPanel({pans}){
返回pans.map(面板=>(
{panel.name}
))
}
render(){
返回(
this.props.panels.map(panel=>(
{panel.name}
)
)
}
}
TabList.propTypes={
面板:React.PropTypes.array
}
导出默认小报列表
如果您有导出默认值
,则在导入
中不需要花括号
import MenuList from './menu/menulist.js'; //correct
import TabList from './menu/tablist.js';
Export {MyComponent, MySecondComponent}; -> import {MyComponent, MySecondComponent} from './path';
Export default MyComponent -> import MyComponent from './path';
谢谢。我已经修复了这个问题,但是现在我遇到了以下错误:ReferenceError:MenuItem未在MenuList.render中定义
import MenuList from './menu/menulist.js'; //correct
import TabList from './menu/tablist.js';
Export {MyComponent, MySecondComponent}; -> import {MyComponent, MySecondComponent} from './path';
Export default MyComponent -> import MyComponent from './path';