React-Router实战：重定向Redirect

当用户访问某界面时，该界面并不存在，此时用Redirect重定向，重新跳到一个我们自定义的组件里。

---

一、基础

• 1、引入使用

// 如果loggedIn 为 false, 则重定向跳转到 /home 页面

import { Route, Redirect } from 'react-router'

<Route exact path="/" render={() => (
  loggedIn ? (
    <Redirect to="/home"/>
  ) : (
    <User />
  )
)}/>

<Redirect
  to={{
    pathname: "/login",
    search: "?utm=your+face",
    state: { referrer: currentLocation }
  }}
/>

二、DOME

1、目录结构

| - index.js
| - components
	| - App      =>   App.js
	| - Home     =>   Home.js
	| - About    =>   About.js
	| - News      =>   News.js

2、源码

./index.js

import React from 'react';
import ReactDOM from 'react-dom';
import App from './components/App/App';
ReactDOM.render(<App />, document.getElementById('root'));

./components/App/App.js

import React , { Component } from 'react';
import { BrowserRouter as Router, Route, NavLink, Switch, Redirect } from 'react-router-dom';
import Home from '../Home/Home';
import About from '../About/About';
import News from '../News/News';

class App extends Component {
  render() {
    return (
      <Router>
        <div>
          <li><NavLink to="/">Home</NavLink></li>
          <li><NavLink to="/about">About</NavLink></li>
          <li><NavLink to="/news">News</NavLink> </li>   <br/>

          <Switch>
            <Route path="/" exact component={Home} />
            <Route path="/about" component={About} />
            <Route path="/news" component={News} />
            <Redirect from="/*" to="/" />
          </Switch>
          
        </div>
      </Router>
    );
  }
}

export default App;

./components/About/About.js

import React, { Component } from 'react';

export default class About extends Component {
    render() {
        return (
            <div>
            	<h2>About</h2>
            </div>
        );
    }
}

./components/New/New.js

import React, { Component } from 'react';

export default class News extends Component {
    render() {
        return (
           <div>
               <h2>News</h2>
           </div>
        );
    }
}

3、show

（1）一切功能都是正常，点击About或News就跳转到 About 或 New界面

（2）但当我要在url中，访问： http://localhost:3000/Login
页面立即会重新跳转，跳转回home界面