关于React动态加载路由处理的相关问题

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

// 异步按需加载component
function 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 })
     })
    }
   }
   //组件将被卸载 
  componentWillUnmount(){ 
    //重写组件的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
   }
  }
 }

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

<Router history={hashHistory}>
    <Route name="home" breadcrumbName="首页" path="/" component={MainLayout}>
      <IndexRoute name="undefined" breadcrumbName="未定义" component={() => <div>未定义</div>}/>
      <Route name="Development" breadcrumbName="施工中" path="Development" component={DevelopmentPage}/>
      <Route breadcrumbName="个人助理" path="CustomerWorkTodo" component={({children}) => <div className="box">{children}</div>}>
        <Route name="Agency" breadcrumbName="待办事项" path="Agency" component={asyncComponent(() => load('GlobalNotification/CustomerWorkAssistantTodo/CustomerAgencyMatter'))}/>
        <Route name="Already" breadcrumbName="已办事项" path="Already" component={asyncComponent(() => load('GlobalNotification/CustomerWorkAssistantTodo/CustomerAlreadyMatter'))}/>
        <Route name="SystemMessage" breadcrumbName="系统消息" path="SystemMessage/:data" component={asyncComponent(() => load('GlobalNotification/SystemMessage/SystemMessage'))}/>
        <Route name="SystemMessagePer" breadcrumbName="系统消息详情" path="SystemMessagePer/:data" component={asyncComponent(() => load('GlobalNotification/SystemMessage/SystemMessagePer'))}/>
      </Route>
    </Router>
 </Router>