withRouter的作用和一个简单应用

import React,{Component} from ‘react‘
import {Switch,Route,NavLink,Redirect,withRouter} from ‘react-router-dom‘ //引入withRouter
import One from ‘./One‘
import NotFound from ‘./NotFound‘
class App extends Component{
    //此时才能获取this.props,包含（history, match, location）三个对象
    console.log(this.props);  //输出{match: {…}, location: {…}, history: {…}, 等}
    render(){return (<div className=‘app‘>
            <NavLink to=‘/one/users‘>用户列表</NavLink>
            <NavLink to=‘/one/companies‘>公司列表</NavLink>
            <Switch>
                <Route path=‘/one/:type?‘ component={One} />
                <Redirect from=‘/‘ to=‘/one‘ exact />
                <Route component={NotFound} />
            </Switch>
        </div>)
    }
}
export default withRouter(App);  //这里要执行一下WithRouter

import React,{Component} from ‘react‘
import {Switch,Route,NavLink,Redirect,withRouter} from  ‘react-router-dom‘
import One from ‘./One‘
import NotFound from ‘./NotFound‘
class App extends Component{
        constructor(props){
                super(props);
                props.history.listen((location)=>{  //在这里监听location对象
                        console.log(location.pathname);  //切换路由的时候输出"/one/users"和"/one/companies"
                        switch(location.pathname){   //根据路径不同切换不同的浏览器title
                                case ‘/one/users‘ : document.title = ‘用户列表‘; break;
                                case ‘/one/companies‘ : document.title = ‘公司列表‘; break;
                                default : break;
                        }
                })
        }
        render(){
                return (<div className=‘app‘>
                        <NavLink to=‘/one/users‘>用户列表</NavLink>
                        <NavLink to=‘/one/companies‘>公司列表</NavLink>
                        <Switch>
                                <Route path=‘/one/:type?‘  component={One} />
                                <Redirect from=‘/‘ to=‘/one‘ exact />
                                <Route component={NotFound} />
                        </Switch>
                </div>)
        }
}
export default withRouter(App);