Fragment 占位组件不生成标签与路由组件lazyLoad案例

<Fragment><Fragment>
<></>

import React, {
    Component, Fragment
} from 'react';
// Fragment表示占位组件 并不会生成一个标签 帮助解决了报错问题 其他什么都不会生成
class Text extends Component {
    render() {
        return (
            <Fragment>
                <input/>
                <ul>
                    <li>Learn More</li>
                    <li>Learn React</li>
                </ul>
            </Fragment>
        );
    }
}
export default Text;

//1.通过React的lazy函数配合import()函数动态加载路由组件 ===> 路由组件代码会被分开打包
const Login = lazy(()=>import('@/pages/Login'))
//2.通过<Suspense>指定在加载得到路由打包文件前显示一个自定义loading界面
<Suspense fallback={<h1>loading.....</h1>}>
       <Switch>
           <Route path="/xxx" component={Xxxx}/>
           <Redirect to="/login"/>
       </Switch>
   </Suspense>

import React, { Component,lazy,Suspense } from 'react'
import { NavLink,Route } from 'react-router-dom'
// import Home from './Home'
// import About from './About'
import Loading from './Loading'
const About = lazy(() => import("./About"))
const Home = lazy(() => import("./Home"))
export default class Demo extends Component {
  render() {
    return (
      <div>
        <div className="row">
        </div>
        <div className="row">
          <div className="col-xs-2 col-xs-offset-2">
            <div className="list-group">
              <NavLink activeClassName="atguigu" className="list-group-item" to="/about">About</NavLink>
              <NavLink activeClassName="atguigu" className="list-group-item" to="/home">Home</NavLink>
            </div>
          </div>
          <div className="col-xs-6">
            <div className="panel">
              <div className="panel-body">
                <Suspense fallback={<Loading/>}>
                    {/* 注册路由 */}
                  <Route path="/about" component={About} />
                  <Route path="/home" component={Home} />
                </Suspense>
              </div>
            </div>
          </div>
          </div>
      </div>
    )
  }
}