Vue初始化项目加载逻辑

Vue初始化项目加载逻辑

项目创建

我们只需要创建项目即可，剩余的依赖都没必要安装

我们先来看main.js,咱们加了一行备注

import Vue from 'vue'
import App from './App.vue'
import router from './router'
import store from './store'

Vue.config.productionTip = false

new Vue({
  router,
  store,
  render: h => h(App)
}).$mount('#app') // 挂载id='app' , 链接到index.html中的app，并使用template引入组件<App>和路由相关的内容。也就是说通过main.js关联到App.vue组件。

通过备注可知，我们首先加载的是App.vue
我们再来看一下App.vue 里都有啥

<template>
  <div id="app">
    <nav>
      
      <router-link to="/">Homerouter-link> |
      <router-link to="/about">Aboutrouter-link>
    nav>
    
    <router-view/>
  div>
template>

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

nav {
  padding: 30px;
}

nav a {
  font-weight: bold;
  color: #2c3e50;
}

nav a.router-link-exact-active {
  color: #42b983;
}
style>

也就是下面这个红框里的内容才是

那下面的内容是哪里来的呢
那就需要看一下路由设置了

import Vue from 'vue'
import VueRouter from 'vue-router'
import HomeView from '../views/HomeView.vue'

Vue.use(VueRouter)

const routes = [
  {
    path: '/',
    name: 'home',
    component: HomeView
  },
  {
    path: '/about',
    name: 'about',
    // route level code-splitting
    // this generates a separate chunk (about.[hash].js) for this route
    // which is lazy-loaded when the route is visited.
    component: () => import(/* webpackChunkName: "about" */ '../views/AboutView.vue')
  }
]

const router = new VueRouter({
  mode: 'history',
  base: process.env.BASE_URL,
  routes
})

export default router

我们看到/目录i指向了home
再想想之前App.vue中的router-view标签，我是这么理解
App.vue是所有标签的父亲，其他的页面都是在它的基础上渲染出来的，所以router-view标签
是必要的，具体表象就是不管是选中了home还是about标签，这两个标签都在，不会消失的

再回来说这个/目录i指向了home
这个HomeView.vue里有什么呢

<template>
  <div class="home">
    <img alt="Vue logo" src="../assets/logo.png">
    <HelloWorld msg="Welcome to Your Vue.js App"/>
  div>
template>

<script>
// @ is an alias to /src
import HelloWorld from '@/components/HelloWorld.vue'

export default {
  name: 'HomeView',
  components: {
    HelloWorld
  }
}
script>

里面有这么个标签

<HelloWorld msg="Welcome to Your Vue.js App"/>

那这个HelloWorld 标签对应的是这两段引入进来通过标签的方式使用的

import HelloWorld from '@/components/HelloWorld.vue'

  components: {
    HelloWorld
  }

那我们就来看看这个HelloWorld.vue里有什么
只截取了template

<template>
  <div class="hello">
    <h1>{{ msg }}h1>
    <p>
      For a guide and recipes on how to configure / customize this project,<br>
      check out the
      <a href="https://cli.vuejs.org" target="_blank" rel="noopener">vue-cli documentationa>.
    p>
    <h3>Installed CLI Pluginsh3>
    <ul>
      <li><a href="https://github.com/vuejs/vue-cli/tree/dev/packages/%40vue/cli-plugin-babel" target="_blank" rel="noopener">babela>li>
      <li><a href="https://github.com/vuejs/vue-cli/tree/dev/packages/%40vue/cli-plugin-router" target="_blank" rel="noopener">routera>li>
      <li><a href="https://github.com/vuejs/vue-cli/tree/dev/packages/%40vue/cli-plugin-vuex" target="_blank" rel="noopener">vuexa>li>
    ul>
    <h3>Essential Linksh3>
    <ul>
      <li><a href="https://vuejs.org" target="_blank" rel="noopener">Core Docsa>li>
      <li><a href="https://forum.vuejs.org" target="_blank" rel="noopener">Foruma>li>
      <li><a href="https://chat.vuejs.org" target="_blank" rel="noopener">Community Chata>li>
      <li><a href="https://twitter.com/vuejs" target="_blank" rel="noopener">Twittera>li>
      <li><a href="https://news.vuejs.org" target="_blank" rel="noopener">Newsa>li>
    ul>
    <h3>Ecosystemh3>
    <ul>
      <li><a href="https://router.vuejs.org" target="_blank" rel="noopener">vue-routera>li>
      <li><a href="https://vuex.vuejs.org" target="_blank" rel="noopener">vuexa>li>
      <li><a href="https://github.com/vuejs/vue-devtools#vue-devtools" target="_blank" rel="noopener">vue-devtoolsa>li>
      <li><a href="https://vue-loader.vuejs.org" target="_blank" rel="noopener">vue-loadera>li>
      <li><a href="https://github.com/vuejs/awesome-vue" target="_blank" rel="noopener">awesome-vuea>li>
    ul>
  div>
template>

其中

<h1>{{ msg }}h1>

的msg就是HomeView.vue的msg传递过来的

<HelloWorld msg="Welcome to Your Vue.js App"/>

其实HomeView啥都没干，只是传了一个值给HelloWorld.vue，内容都是HelloWorld.vue的

我们再来看一下AboutView.vue里都有啥吧

<template>
  <div class="about">
    <h1>This is an about pageh1>
  div>
template>

很简单，就只是一个标题而已，对应的页面也是这样的