ElementUI完整引入及按需引入项目开发

 npm i element-ui -S

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

import ElementUI from 'element-ui'
import 'element-ui/lib/theme-chalk/index.css'
Vue.use(ElementUI)

Vue.config.productionTip = false

new Vue({
  el: '#app',
  components: { App },
  template: '<App/>'
})

npm install babel-plugin-component -D

module.exports = {
  presets: [
    '@vue/cli-plugin-babel/preset'
  ],
  "plugins": [
    [
      "component",
      {
        "libraryName": "element-ui",
        "styleLibraryName": "theme-chalk"
      }
    ]
  ]
}

// import ElementUI from 'element-ui'
// import 'element-ui/lib/theme-chalk/index.css'
// Vue.use(ElementUI)

import {
  Button,
  ButtonGroup,
} from 'element-ui';

Vue.use(Button).use(ButtonGroup)