使用vue-cli3新建一个项目并写好基本配置(推荐)

module.exports = {
 devServer: {
  port: 8100, // 端口号
 }
}

{
 "dev": {
 "serverUrl": "http://localhost:57156/"
 },
 "build": {
 "serverUrl": "http://build.com/",
 "outputDir": "../../dist/build",      
 "productId": "111"
 },
 "alpha": {
 "serverUrl": "http://build-test.com/",
 "outputDir": "../../dist/alpha",
 "productId": "222"
 }
}

var path = require('path')
var appconf = require('../../appconf.json')
var serverurl
var productId = ''
switch (process.env.NODE_ENV) {
 case 'production':
  serverurl = appconf.build.serverUrl
  productId = appconf.build.productId
  break
 case 'development':
  serverurl = appconf.dev.serverUrl
  break
 case 'alpha':
  serverurl = appconf.alpha.serverUrl
  productId = appconf.alpha.productId
  break
}
// 配置 build 文件输出路径, 可以使用绝对路径或相对路径
var outputDir
var reg = /^\.(\.)?\/.*/
if (reg.test(appconf.build.outputDir)) {
 if (process.env.NODE_ENV == 'alpha')
  outputDir = path.resolve(__dirname, appconf.alpha.outputDir) // 相对路径
 else
  outputDir = path.resolve(__dirname, appconf.build.outputDir) // 相对路径
} else {
 if (process.env.NODE_ENV == 'alpha')
  outputDir = appconf.alpha.outputDir
 else
  outputDir = appconf.build.outputDir // 绝对路径
}
var conf = {
 outputDir: outputDir,
 serverUrl: serverurl,
 env: process.env.NODE_ENV,
 productId: productId
}
module.exports = conf

{
 ···
 "scripts": {
 "serve": "vue-cli-service serve",
 "alpha": "vue-cli-service build --mode alpha",
 "build": "vue-cli-service build"
 }
 ···
}

var { outputDir } = require('./src/common/configByEnv.js');
module.exports = {
 outputDir: outputDir,
 ···
}

{
 ··· 
 "postcss": {
 "plugins": {
  "postcss-cssnext": {}
 }
 },
 ··· 
}

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