问vue.js 组件加载问题？

import Vue from 'vue'

import Router from 'vue-router'

Vue.use(Router)

export function createRouter () {

  return new Router({

    mode: 'history',

    routes: [

      { path: '/', component: () => import('./components/Home.vue') },

      { path: '/item/:id', component: () => import('./components/Item.vue') }

    ]

  })

}

import Vue from 'vue'

import Router from 'vue-router'

Vue.use(Router)

export function createRouter () {

  return new Router({

    mode: 'history',

    routes: [

      { path: '/', component: resolve => require(['./components/Home.vue'],resolve) },

      { path: '/item/:id', component: resolve => require(['./components/Item.vue'],resolve) }

    ]

  })

}