vue3如何按需加载第三方组件库详解

yarn add element-plus
# OR
npm install element-plus --save

import { createApp } from 'Vue'
import ElementPlus from 'element-plus';
import 'element-plus/lib/theme-chalk/index.CSS';
import App from './App.vue';

const app = createApp(App)
app.use(ElementPlus)
app.mount('#app')

yarn add vite-plugin-importer
# OR
npm install vite-plugin-importer --save

import { defineConfig } from 'vite'
import vue from '@vitejs/plugin-vue'
import usePluginImport from 'vite-plugin-importer'

// https://vitejs.dev/config/
export default defineConfig({
  plugins: [
    vue(),
    usePluginImport({
      libraryName: 'element-plus',
      customStyleName: (name) => {
        return `element-plus/lib/theme-chalk/${name}.css`;
      },
    }),
  ],
  resolve: {
    alias: {
      'vue': 'vue/dist/vue.esm-bundler.js'
    },
  },
})

import { createApp } from 'vue'
import App from './App.vue'
import { ElButton, ElSelect } from 'element-plus';

const app = createApp(App)
app.component(ElButton.name, ElButton);
app.component(ElSelect.name, ElSelect);
app.mount('#app')

yarn add vite-plugin-style-import -D
# OR
npm i vite-plugin-style-import -D

import { defineConfig } from 'vite'
import vue from '@vitejs/plugin-vue'
import styleImport from 'vite-plugin-style-import';

// Https://vitejs.dev/config/
export default defineConfig({
  plugins: [
    vue(),
    styleImport({
      libs: [
        {
          libraryName: 'element-plus',
          esModule: true,
          ensureStyleFile: true,
          resolveStyle: (name) => {
            return `element-plus/lib/theme-chalk/${name}.css`;
          },
          resolveComponent: (name) => {
            return `element-plus/lib/${name}`;
          },
        },
      ],
    }),
  ],
  resolve: {
    alias: {
      'vue': 'vue/dist/vue.esm-bundler.js' 
    },
  },
})

import { createApp } from 'vue'
import App from './App.vue'
import { ElButton, ElSelect } from 'element-plus';

const app = createApp(App)
app.component(ElButton.name, ElButton);
app.component(ElSelect.name, ElSelect);
app.mount('#app')