vue-element-admin配置后端接口解决跨域问题

1. 修改 .env.development文件
   添加VUE_APP_BASE_DOMAIN和VUE_APP_BASE_API

# just a flag
ENV='development'# base api# VUE_APP_BASE_API = '/dev-api'
VUE_APP_BASE_DOMAIN='http://www.xxxx.com'
VUE_APP_BASE_API='/admin-api'

说明：VUE_APP_BASE_DOMAIN为接口域名地址,VUE_APP_BASE_API为域名后面的接口前缀<这个在页面审查元素看到，可以和实际的接口前缀不同>

2. 修改vue.config.js文件
   在devServer下面添加proxy并注释掉before: require(’./mock/mock-server.js’)

module.exports={
  /**
   * You will need toset publicPathif you plan to deploy your site under a sub path,
   *for example GitHub Pages. If you plan to deploy your site to https://foo.github.io/bar/,
   *then publicPath should beset to"/bar/".
   * Inmost cases please use'/'!!!
   * Detail: https://cli.vuejs.org/config/#publicpath
   */
  publicPath:'/',
  outputDir:'dist',
  assetsDir:'static',
  lintOnSave: process.env.NODE_ENV==='development',
  productionSourceMap: false,
  devServer:{
    port: port,
    open: true,
    overlay:{
      warnings: false,
      errors:true},
    proxy:{[process.env.VUE_APP_BASE_API]:{
        target: process.env.VUE_APP_BASE_DOMAIN,
        changeOrigin: true,  //配置跨域
        ws: true,
        pathRewrite:{['^' + process.env.VUE_APP_BASE_API]:'/admin-api'}}}
    // before: require('./mock/mock-server.js')},

3. 重新执行npm run dev, 接口请求成功