const asyncModal = () => import('./Modal.vue')

const asyncModal = {
  component: () => import('./Modal.vue'),
  delay: 200,
  timeout: 3000,
  error: ErrorComponent,
  loading: LoadingComponent
}

<template>
   <div>
   app
   <async></async>
   </div>
</template>

<script>
import {defineAsyncComponent} from "vue"
//不带配置的异步组件
export default{
   components:{
      //AsyncCom指定要加载的组件的名称，把defineAsyncComponent放进去尽可以定义一个异步组件了
      async:defineAsyncComponent(()=>import("./components/next.vue"))
   }
}
</script>

const AsyncComWithOptions=defineAsyncComponent({
  // 这里之前是compoent改为loader
  loader:()=>import ('./components/Nextpage')，
  delay:20,
  timeout:3000,
  error:ErrorCompoent,
  loading:LoadingComponent
})

 loader:()=>new Pomise((resolve,reject)=>{
    resolve({
      template:'<div>我是异步组件</div>'
    })
  }),