3.vue3项目结构

3.1.main.js

//引入的不再是Vue的构造函数，引入的是一个名为createApp的工厂函数
import { createApp } from 'vue'
import App from './App.vue'

// createApp(App).mount('#app')

//创建应用实例对象-app(类似于Vue2中的vm，但app比vm更‘轻’)
const app = createApp(App)
//挂载
app.mount('#app')

3.2.关闭语法检查

vue.config.js

const { defineConfig } = require('@vue/cli-service')
module.exports = defineConfig({
  //关闭语法检查
  lintOnSave: false,
  transpileDependencies: true
})

3.3.App.vue

<template>
  <!--vue3的组件中的模板结构可以没有根标签-->
  <img alt="Vue logo" src="./assets/logo.png">
  <HelloWorld msg="Welcome to Your Vue.js App"/>
</template>

<script>
import HelloWorld from './components/HelloWorld.vue'

export default {
  name: 'App',
  components: {
    HelloWorld
  }
}
</script>

<style>
#app {
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
  margin-top: 60px;
}
</style>