React路由

react-router-dom的理解

1. react的一个插件库。

2. 专门用来实现一个SPA应用。

3. 基于react的项目基本都会用到此库。

react-router-dom相关API

内置组件

1. <BrowserRouter>

2. <HashRouter>

3. <Route>

4. <Redirect>

5. <Link>

6. <NavLink>

7. <Switch>

其它

1. history对象

2. match对象

3. withRouter函数

路由的基本使用

准备

下载react-router-dom:

基本使用

index.js文件

//引入react核心库
import React from 'react'
//引入ReactDOM
import ReactDOM from 'react-dom'
//
import {BrowserRouter} from 'react-router-dom'
//引入App
import App from './App'

ReactDOM.render(
	<BrowserRouter>
		<App/>
	</BrowserRouter>,
	document.getElementById('root')
)

App.jsx文件

import React, { Component } from 'react'
import {Link,Route} from 'react-router-dom'
import Home from './components/Home'
import About from './components/About'

export default class App extends Component {
	render() {
		return (
			<div>
				<div className="row">
					<div className="col-xs-offset-2 col-xs-8">
						<div className="page-header"><h2>React Router Demo</h2></div>
					</div>
				</div>
				<div className="row">
					<div className="col-xs-2 col-xs-offset-2">
						<div className="list-group">

							{/* 原生html中，靠<a>跳转不同的页面 */}
							{/* <a className="list-group-item" href="./about.html">About</a>
							<a className="list-group-item active" href="./home.html">Home</a> */}

							{/* 在React中靠路由链接实现切换组件--编写路由链接 */}
							<Link className="list-group-item" to="/about">About</Link>
							<Link className="list-group-item" to="/home">Home</Link>
						</div>
					</div>
					<div className="col-xs-6">
						<div className="panel">
							<div className="panel-body">
								{/* 注册路由 */}
								<Route path="/about" component={About}/>
								<Route path="/home" component={Home}/>
							</div>
						</div>
					</div>
				</div>
			</div>
		)
	}
}

1. 明确界面中的展示区和导航区
2. 导航区的a标签改为linke标签
   1. <Link to="/xxx" >Demo</Link>
3. 展示区写Route标签进行路由匹配
   1. <Route path="/xxx" component={xxx}>
4. App最外侧包裹一个<BrowerRouter></BrowerRouter>
5. 注意以上写法是用于React5及其以下版本

路由组件与一般组件的不同

1. 写法不同：

​ 一般组件：<Demo/>

​ 路由组件：<Route path="/demo" component={Demo}/>

2. 存放位置不同：

​ 一般组件：components

​ 路由组件：pages

3. 接收到的props不同：

​ 一般组件：写组件标签时传递了什么，就能收到什么

​ 路由组件：接收到三个固定的属性

           history:

​              go: ƒ go(n)

​              goBack: ƒ goBack()

​              goForward: ƒ goForward()

​              push: ƒ push(path, state)

​              replace: ƒ replace(path, state)

​           location:

​              pathname: "/about"

​              search: ""

​              state: undefined

​           match:

​              params: {}

​              path: "/about"

​              url: "/about"

Switch的使用

​ 1.通常情况下，path和component是一一对应的关系。

​ 2.Switch可以提高路由匹配效率(单一匹配)。

import React, { Component } from 'react'
import {Route,Switch} from 'react-router-dom'
import Home from './pages/Home' //Home是路由组件
import About from './pages/About' //About是路由组件
import Header from './components/Header' //Header是一般组件
import MyNavLink from './components/MyNavLink'
import Test from './pages/Test'

export default class App extends Component {
	render() {
		return (
			<div>
				<div className="row">
					<div className="col-xs-offset-2 col-xs-8">
						<Header/>
					</div>
				</div>
				<div className="row">
					<div className="col-xs-2 col-xs-offset-2">
						<div className="list-group">

							{/* 原生html中，靠<a>跳转不同的页面 */}
							{/* <a className="list-group-item" href="./about.html">About</a>
							<a className="list-group-item active" href="./home.html">Home</a> */}

							{/* 在React中靠路由链接实现切换组件--编写路由链接 */}
							<MyNavLink to="/about">About</MyNavLink>
							<MyNavLink to="/home">Home</MyNavLink>
						</div>
					</div>
					<div className="col-xs-6">
						<div className="panel">
							<div className="panel-body">
								{/* 注册路由 */}
								<Switch>
									<Route path="/about" component={About}/>
									<Route path="/home" component={Home}/>
									<Route path="/home" component={Test}/>
								</Switch>
							</div>
						</div>
					</div>
				</div>
			</div>
		)
	}
}

路由的精准匹配与模糊匹配

1. 默认使用的是模糊匹配（简单记：【输入的路径】必须包含要【匹配的路径】，且顺序要一致）

2. 开启严格匹配：<Route exact={true} path="/about" component={About}/>

3. 严格匹配不要随便开启，需要再开，有些时候开启会导致无法继续匹配二级路由

import React, { Component } from 'react'
import {Route,Switch} from 'react-router-dom'
import Home from './pages/Home' //Home是路由组件
import About from './pages/About' //About是路由组件
import Header from './components/Header' //Header是一般组件
import MyNavLink from './components/MyNavLink'

export default class App extends Component {
	render() {
		return (
			<div>
				<div className="row">
					<div className="col-xs-offset-2 col-xs-8">
						<Header/>
					</div>
				</div>
				<div className="row">
					<div className="col-xs-2 col-xs-offset-2">
						<div className="list-group">

							{/* 原生html中，靠<a>跳转不同的页面 */}
							{/* <a className="list-group-item" href="./about.html">About</a>
							<a className="list-group-item active" href="./home.html">Home</a> */}

							{/* 在React中靠路由链接实现切换组件--编写路由链接 */}
							<MyNavLink to="/about">About</MyNavLink>
							<MyNavLink to="/home/a/b">Home</MyNavLink>
						</div>
					</div>
					<div className="col-xs-6">
						<div className="panel">
							<div className="panel-body">
								{/* 注册路由 */}
								<Switch>
									<Route exact path="/about" component={About}/>
									<Route exact path="/home" component={Home}/>
								</Switch>
							</div>
						</div>
					</div>
				</div>
			</div>
		)
	}
}

Redirect的使用

1. 一般写在所有路由注册的最下方，当所有路由都无法匹配时，跳转到Redirect指定的路由

2. 具体编码：

<Switch>
	<Route path="/about" component={About}/>
	<Route path="/home" component={Home}/>
	<Redirect to="/about"/>
</Switch>

import React, { Component } from 'react'
import {Route,Switch,Redirect} from 'react-router-dom'
import Home from './pages/Home' //Home是路由组件
import About from './pages/About' //About是路由组件
import Header from './components/Header' //Header是一般组件
import MyNavLink from './components/MyNavLink'

export default class App extends Component {
	render() {
		return (
			<div>
				<div className="row">
					<div className="col-xs-offset-2 col-xs-8">
						<Header/>
					</div>
				</div>
				<div className="row">
					<div className="col-xs-2 col-xs-offset-2">
						<div className="list-group">

							{/* 原生html中，靠<a>跳转不同的页面 */}
							{/* <a className="list-group-item" href="./about.html">About</a>
							<a className="list-group-item active" href="./home.html">Home</a> */}

							{/* 在React中靠路由链接实现切换组件--编写路由链接 */}
							<MyNavLink to="/about">About</MyNavLink>
							<MyNavLink to="/home">Home</MyNavLink>
						</div>
					</div>
					<div className="col-xs-6">
						<div className="panel">
							<div className="panel-body">
								{/* 注册路由 */}
								<Switch>
									<Route path="/about" component={About}/>
									<Route path="/home" component={Home}/>
									<Redirect to="/about"/>
								</Switch>
							</div>
						</div>
					</div>
				</div>
			</div>
		)
	}
}

嵌套路由

1. 注册子路由时要写上父路由的path值

2. 路由的匹配是按照注册路由的顺序进行的

import React, { Component } from 'react'
import MyNavLink from '../../components/MyNavLink'
import {Route,Switch,Redirect} from 'react-router-dom'
import News from './News'
import Message from './Message'

export default class Home extends Component {
	render() {
		return (
				<div>
					<h3>我是Home的内容</h3>
					<div>
						<ul className="nav nav-tabs">
							<li>
								<MyNavLink to="/home/news">News</MyNavLink>
							</li>
							<li>
								<MyNavLink to="/home/message">Message</MyNavLink>
							</li>
						</ul>
						{/* 注册路由 */}
						<Switch>
							<Route path="/home/news" component={News}/>
							<Route path="/home/message" component={Message}/>
							<Redirect to="/home/news"/>
						</Switch>
					</div>
				</div>
			)
	}
}

向路由组件传递参数

1. params参数

​ 路由链接(携带参数)：<Link to='/demo/test/tom/18'}>详情</Link>

​ 注册路由(声明接收)：<Route path="/demo/test/:name/:age" component={Test}/>

​ 接收参数：this.props.match.params

Message组件的代码：

import React, { Component } from 'react'
import {Link,Route} from 'react-router-dom'
import Detail from './Detail'

export default class Message extends Component {
	state = {
		messageArr:[
			{id:'01',title:'消息1'},
			{id:'02',title:'消息2'},
			{id:'03',title:'消息3'},
		]
	}
	render() {
		const {messageArr} = this.state
		return (
			<div>
				<ul>
					{
						messageArr.map((msgObj)=>{
							return (
								<li key={msgObj.id}>
									{/* 向路由组件传递params参数 */}
									<Link to={`/home/message/detail/${msgObj.id}/${msgObj.title}`}>{msgObj.title}</Link>
								</li>
							)
						})
					}
				</ul>
				<hr/>
				{/* 声明接收params参数 */}
				<Route path="/home/message/detail/:id/:title" component={Detail}/>
			</div>
		)
	}
}

Detail组件的代码

import React, { Component } from 'react'

const DetailData = [
	{id:'01',content:'你好，中国'},
	{id:'02',content:'你好，尚硅谷'},
	{id:'03',content:'你好，未来的自己'}
]
export default class Detail extends Component {
	render() {
		console.log(this.props);
		// 接收params参数
		const {id,title} = this.props.match.params
		const findResult = DetailData.find((detailObj)=>{
			return detailObj.id === id
		})
		return (
			<ul>
				<li>ID:{id}</li>
				<li>TITLE:{title}</li>
				<li>CONTENT:{findResult.content}</li>
			</ul>
		)
	}
}

2. search参数

​ 路由链接(携带参数)：<Link to='/demo/test?name=tom&age=18'}>详情</Link>

​ 注册路由(无需声明，正常注册即可)：<Route path="/demo/test" component={Test}/>

​ 接收参数：this.props.location.search

​ 备注：获取到的search是urlencoded编码字符串，需要借助querystring解析

Message组件代码

import React, { Component } from 'react'
import {Link,Route} from 'react-router-dom'
import Detail from './Detail'

export default class Message extends Component {
	state = {
		messageArr:[
			{id:'01',title:'消息1'},
			{id:'02',title:'消息2'},
			{id:'03',title:'消息3'},
		]
	}
	render() {
		const {messageArr} = this.state
		return (
			<div>
				<ul>
					{
						messageArr.map((msgObj)=>{
							return (
								<li key={msgObj.id}>

									{/* 向路由组件传递params参数 */}
									{/* <Link to={`/home/message/detail/${msgObj.id}/${msgObj.title}`}>{msgObj.title}</Link> */}

									{/* 向路由组件传递search参数 */}
									<Link to={`/home/message/detail/?id=${msgObj.id}&title=${msgObj.title}`}>{msgObj.title}</Link>

								</li>
							)
						})
					}
				</ul>
				<hr/>
				{/* 声明接收params参数 */}
				{/* <Route path="/home/message/detail/:id/:title" component={Detail}/> */}

				{/* search参数无需声明接收，正常注册路由即可 */}
				<Route path="/home/message/detail" component={Detail}/>

			</div>
		)
	}
}

Detail组件的代码

import React, { Component } from 'react'
import qs from 'querystring'

const DetailData = [
	{id:'01',content:'你好，中国'},
	{id:'02',content:'你好，尚硅谷'},
	{id:'03',content:'你好，未来的自己'}
]
export default class Detail extends Component {
	render() {
		console.log(this.props);

		// 接收params参数
		// const {id,title} = this.props.match.params 

		// 接收search参数
		const {search} = this.props.location
		const {id,title} = qs.parse(search.slice(1))

		const findResult = DetailData.find((detailObj)=>{
			return detailObj.id === id
		})
		return (
			<ul>
				<li>ID:{id}</li>
				<li>TITLE:{title}</li>
				<li>CONTENT:{findResult.content}</li>
			</ul>
		)
	}
}

3. state参数

​ 路由链接(携带参数)：<Link to={{pathname:'/demo/test',state:{name:'tom',age:18}}}>详情</Link>

​ 注册路由(无需声明，正常注册即可)：<Route path="/demo/test" component={Test}/>

​ 接收参数：this.props.location.state

​ 备注：刷新也可以保留住参数
Message组件代码

import React, { Component } from 'react'
import {Link,Route} from 'react-router-dom'
import Detail from './Detail'

export default class Message extends Component {
	state = {
		messageArr:[
			{id:'01',title:'消息1'},
			{id:'02',title:'消息2'},
			{id:'03',title:'消息3'},
		]
	}
	render() {
		const {messageArr} = this.state
		return (
			<div>
				<ul>
					{
						messageArr.map((msgObj)=>{
							return (
								<li key={msgObj.id}>

									{/* 向路由组件传递params参数 */}
									{/* <Link to={`/home/message/detail/${msgObj.id}/${msgObj.title}`}>{msgObj.title}</Link> */}

									{/* 向路由组件传递search参数 */}
									{/* <Link to={`/home/message/detail/?id=${msgObj.id}&title=${msgObj.title}`}>{msgObj.title}</Link> */}

									{/* 向路由组件传递state参数 */}
									<Link to={{pathname:'/home/message/detail',state:{id:msgObj.id,title:msgObj.title}}}>{msgObj.title}</Link>

								</li>
							)
						})
					}
				</ul>
				<hr/>
				{/* 声明接收params参数 */}
				{/* <Route path="/home/message/detail/:id/:title" component={Detail}/> */}

				{/* search参数无需声明接收，正常注册路由即可 */}
				{/* <Route path="/home/message/detail" component={Detail}/> */}

				{/* state参数无需声明接收，正常注册路由即可 */}
				<Route path="/home/message/detail" component={Detail}/>

			</div>
		)
	}
}

Detail组件代码

import React, { Component } from 'react'
// import qs from 'querystring'

const DetailData = [
	{id:'01',content:'你好，中国'},
	{id:'02',content:'你好，尚硅谷'},
	{id:'03',content:'你好，未来的自己'}
]
export default class Detail extends Component {
	render() {
		console.log(this.props);

		// 接收params参数
		// const {id,title} = this.props.match.params 

		// 接收search参数
		// const {search} = this.props.location
		// const {id,title} = qs.parse(search.slice(1))

		// 接收state参数
		const {id,title} = this.props.location.state || {}

		const findResult = DetailData.find((detailObj)=>{
			return detailObj.id === id
		}) || {}
		return (
			<ul>
				<li>ID:{id}</li>
				<li>TITLE:{title}</li>
				<li>CONTENT:{findResult.content}</li>
			</ul>
		)
	}
}

编程式路由导航

​ 借助this.prosp.history对象上的API对操作路由跳转、前进、后退

• this.prosp.history.push()

• this.prosp.history.replace()

• this.prosp.history.goBack()

• this.prosp.history.goForward()

• this.prosp.history.go()

Message组件代码

import React, { Component } from 'react'
import {Link,Route} from 'react-router-dom'
import Detail from './Detail'

export default class Message extends Component {
	state = {
		messageArr:[
			{id:'01',title:'消息1'},
			{id:'02',title:'消息2'},
			{id:'03',title:'消息3'},
		]
	}

	replaceShow = (id,title)=>{
		//replace跳转+携带params参数
		//this.props.history.replace(`/home/message/detail/${id}/${title}`)

		//replace跳转+携带search参数
		// this.props.history.replace(`/home/message/detail?id=${id}&title=${title}`)

		//replace跳转+携带state参数
		this.props.history.replace(`/home/message/detail`,{id,title})
	}

	pushShow = (id,title)=>{
		//push跳转+携带params参数
		// this.props.history.push(`/home/message/detail/${id}/${title}`)

		//push跳转+携带search参数
		// this.props.history.push(`/home/message/detail?id=${id}&title=${title}`)

		//push跳转+携带state参数
		this.props.history.push(`/home/message/detail`,{id,title})
		
	}

	back = ()=>{
		this.props.history.goBack()
	}

	forward = ()=>{
		this.props.history.goForward()
	}

	go = ()=>{
		this.props.history.go(-2)
	}

	render() {
		const {messageArr} = this.state
		return (
			<div>
				<ul>
					{
						messageArr.map((msgObj)=>{
							return (
								<li key={msgObj.id}>

									{/* 向路由组件传递params参数 */}
									{/* <Link to={`/home/message/detail/${msgObj.id}/${msgObj.title}`}>{msgObj.title}</Link> */}

									{/* 向路由组件传递search参数 */}
									{/* <Link to={`/home/message/detail/?id=${msgObj.id}&title=${msgObj.title}`}>{msgObj.title}</Link> */}

									{/* 向路由组件传递state参数 */}
									<Link to={{pathname:'/home/message/detail',state:{id:msgObj.id,title:msgObj.title}}}>{msgObj.title}</Link>

									&nbsp;<button onClick={()=> this.pushShow(msgObj.id,msgObj.title)}>push查看</button>
									&nbsp;<button onClick={()=> this.replaceShow(msgObj.id,msgObj.title)}>replace查看</button>
								</li>
							)
						})
					}
				</ul>
				<hr/>
				{/* 声明接收params参数 */}
				{/* <Route path="/home/message/detail/:id/:title" component={Detail}/> */}

				{/* search参数无需声明接收，正常注册路由即可 */}
				{/* <Route path="/home/message/detail" component={Detail}/> */}

				{/* state参数无需声明接收，正常注册路由即可 */}
				<Route path="/home/message/detail" component={Detail}/>

				<button onClick={this.back}>回退</button>&nbsp;
				<button onClick={this.forward}>前进</button>&nbsp;
				<button onClick={this.go}>go</button>

			</div>
		)
	}
}

withRouter的使用

普通组件Header组件中的代码

import React, { Component } from 'react'
import {withRouter} from 'react-router-dom'

class Header extends Component {

	back = ()=>{
		this.props.history.goBack()
	}

	forward = ()=>{
		this.props.history.goForward()
	}

	go = ()=>{
		this.props.history.go(-2)
	}

	render() {
		console.log('Header组件收到的props是',this.props);
		return (
			<div className="page-header">
				<h2>React Router Demo</h2>
				<button onClick={this.back}>回退</button>&nbsp;
				<button onClick={this.forward}>前进</button>&nbsp;
				<button onClick={this.go}>go</button>
			</div>
		)
	}
}

export default withRouter(Header)

//withRouter可以加工一般组件，让一般组件具备路由组件所特有的API
//withRouter的返回值是一个新组件

BrowserRouter与HashRouter的区别

1.底层原理不一样：

​ BrowserRouter使用的是H5的history API，不兼容IE9及以下版本。

​ HashRouter使用的是URL的哈希值。

2.path表现形式不一样

​ BrowserRouter的路径中没有#,例如：localhost:3000/demo/test

​ HashRouter的路径包含#,例如：localhost:3000/#/demo/test

3.刷新后对路由state参数的影响

​ (1).BrowserRouter没有任何影响，因为state保存在history对象中。

​ (2).HashRouter刷新后会导致路由state参数的丢失！！！

4.备注：HashRouter可以用于解决一些路径错误相关的问题。