我们使用脚手架创建的项目，可以在config项目中看到

其中我们打开index.js文件

'use strict'
// Template version: 1.3.1
// see http://vuejs-templates.github.io/webpack for documentation.

const path = require('path')module.exports = {dev: {// PathsassetsSubDirectory: 'static',assetsPublicPath: '/',proxyTable: {'/api': {target: 'http://192.168.0.173:8080',changeOrigin:true,//允许跨域pathRewrite: {'^/api': '/api'}}},// Various Dev Server settingshost: '0.0.0.0', // 代理会映射到本地的一个ip地址。这里我们可以通过改成根基的ip地址或者0.0.0.0然后通过手机就可以看到项目port: 8080, // 这里是我们本地设置的一个端口号autoOpenBrowser: false,errorOverlay: true,notifyOnErrors: true,poll: false, // https://webpack.js.org/configuration/dev-server/#devserver-watchoptions-/*** Source Maps*/// https://webpack.js.org/configuration/devtool/#developmentdevtool: 'cheap-module-eval-source-map',// If you have problems debugging vue-files in devtools,// set this to false - it *may* help// https://vue-loader.vuejs.org/en/options.html#cachebustingcacheBusting: true,cssSourceMap: true},build: {// Template for index.htmlindex: path.resolve(__dirname, '../dist/index.html'),// PathsassetsRoot: path.resolve(__dirname, '../dist'),assetsSubDirectory: 'static',assetsPublicPath: '/',/*** Source Maps*/productionSourceMap: true,// https://webpack.js.org/configuration/devtool/#productiondevtool: '#source-map',// Gzip off by default as many popular static hosts such as// Surge or Netlify already gzip all static assets for you.// Before setting to `true`, make sure to:// npm install --save-dev compression-webpack-pluginproductionGzip: false,productionGzipExtensions: ['js', 'css'],// Run the build command with an extra argument to// View the bundle analyzer report after build finishes:// `npm run build --report`// Set to `true` or `false` to always turn it on or off
    bundleAnalyzerReport: process.env.npm_config_report}
}

其中proxyTable就是创建项目所自带的代理，当我们运行dev的时候，就会通过访问代理来间接访问我们的api。只需要添加属性changeOrigin:true 就可以实现跨域访问。同时可以提高安全系数。也省去了我们自定义请求文件时，所添加的主域！