一、简介

        react router是一个构建基于react应用的路由管理库。允许你在程序中定义不同的路由和导航规则。以实现不同的url路径显示不同的组件。

二、相关技术

<Router><div><ul id = "menu"><li><Link to = "/home">Home</Link></li><li><Link to = "/hello">Hello</Link></li><li><Link to = "/about">About</Link></li></ul><div id = "page-container"><Route path = "/home" component = {Home} /><Route path = "/hello" component = {Hello} /><Route path = "/about" component = {About} /></div></div>
</Router>

Link实现导航跳转

Route 配置路由定义，对应组件会填充父组件。

React Router API

Link -> <Link to = '/about'>About</Link> 普通连接，不会触发浏览器刷新

NavLink ->  <NavLink to = '/about' activieClassName = "selected">About</NavLink >       

Prompt ->

 <Prompt when = {fromIsHalfFilledOut}  message = "Are you sure you want to leave"/>

Redirect -> 

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

url传参

react 组件可以通过 match props 获取Route 中url对应的占位符值。

// 通过match属性获取Route Path中的占位符值
const Topic = ({match}) => (<h1>Topic {match.params.id}</h1>
); export default class RouterParams extends React.PureComponent{render(){return (<Router><div><ul id = "menu"><li><Link to = '/topic/1'>Topic 1</Link></li><li><Link to = '/topic/2'>Topic 2</Link></li><li><Link to = '/topic/3'>Topic 3</Link></li></ul><div id = "page-container"><Route path = "/topic/:id" component = {Topic} /></div></div></Router>);}}

默认情况下，直接修改浏览器地址是不会触发跳转的，必须通过Link或者其它React routeApi实现跳转。

嵌套路由

1.每个React组件都是路由容器。

2.React Router的声明式语法可以方便的定义嵌套路由。

举个多级目录嵌套路由例子

// 一级目录
export const Category = () => {return () => {<Router><div><ul id = "menu"><li><Link to = "/category/1">Category 1</Link></li><li><Link to = "/category/2">Category 2</Link></li><li><Link to = "/category/3">Category 3</Link></li></ul><div id = "nav-container"><Route path = "/category/:id" component = {SubCategory}></div></div></Router>}
}// 二级目录
export const SecondCategory = ({match}) => {return () => {<Router><div><ul id = "menu"><li><Link to = "/category/${match.params.id}/sub/1">Category 1</Link></li><li><Link to = "/category/${match.params.id}/sub/2">Category 2</Link></li><li><Link to = "/category/${match.params.id}/sub/3">Category 3</Link></li></ul><div id = "page-container"><Route path = "/category/:id/sub/:subId" component = {Page}></div></div>            </Router>}
}// 页面内容
export const Page = ({match}) =>{const data = getPageData(match.params.id, match.params.subid);return parseData(data);
}