前言

相信很多人都遇到過想在React項目中動態加載路由這種問題，接下來我們逐步實現。

引入必要的依賴

import React from 'react'import { Router, Route, IndexRoute, hashHistory } from 'react-router'

接下來創建一個component函數

目的就是為了變為router的component實現異步加載。

// 異步按需加載componentfunction asyncComponent(getComponent) {  return class AsyncComponent extends React.Component {   static Component = null;   state = { Component: AsyncComponent.Component };    componentDidMount() {    if (!this.state.Component) {     getComponent().then(({default: Component}) => {      AsyncComponent.Component = Component      this.setState({ Component })     })    }   }   //組件將被卸載   componentWillUnmount(){     //重寫組件的setState方法，直接返回空    this.setState = (state,callback)=>{      return;    };   }   render() {    const { Component } = this.state    if (Component) {     return <Component {...this.props} />    }    return null   }  } }

在此說明componentWillUnmount鉤子是為了解決Can only update a mounted or mounting component的這個問題，原因是當離開頁面以后，組件已經被卸載，執行setState時無法找到渲染組件。

接下來實現本地文件路徑的傳入

 function load(component) {  return import(`./routes/${component}`) }

將已知地址路徑傳遞到一個函數并把這個函數作為參數傳遞到 asyncComponent中這樣asyncComponent就能接收到這個路由的地址了，然后我們要做的就是將這個asyncComponent函數帶入到router中。

<Router history={hashHistory}>    <Route name="home" breadcrumbName="首頁" path="/" component={MainLayout}>      <IndexRoute name="undefined" breadcrumbName="未定義" component={() => <div>未定義</div>}/>      <Route name="Development" breadcrumbName="施工中" path="Development" component={DevelopmentPage}/>      <Route breadcrumbName="個人助理" path="CustomerWorkTodo" component={({children}) => <div className="box">{children}</div>}>        <Route name="Agency" breadcrumbName="待辦事項" path="Agency" component={asyncComponent(() => load('GlobalNotification/CustomerWorkAssistantTodo/CustomerAgencyMatter'))}/>        <Route name="Already" breadcrumbName="已辦事項" path="Already" component={asyncComponent(() => load('GlobalNotification/CustomerWorkAssistantTodo/CustomerAlreadyMatter'))}/>        <Route name="SystemMessage" breadcrumbName="系統消息" path="SystemMessage/:data" component={asyncComponent(() => load('GlobalNotification/SystemMessage/SystemMessage'))}/>        <Route name="SystemMessagePer" breadcrumbName="系統消息詳情" path="SystemMessagePer/:data" component={asyncComponent(() => load('GlobalNotification/SystemMessage/SystemMessagePer'))}/>      </Route>    </Router> </Router>