创建request.js

import axios from "axios";
import qs from "qs";   // 数据序列化处理
//添加请求拦截器
axios.interceptors.request.use(
  config => {
    if (config.method === 'post') {
      config.data = qs.stringify(config.data)
    }
    return config;
  },
  error => {
    return Promise.reject(error);
  }
);
//添加响应拦截器
axios.interceptors.response.use(
  response => {
    return response;
  },
  error => {
    return Promise.resolve(error.response);
  }
);

axios.defaults.baseURL = "https://baidu.com"; //接口地址（在本地测试的时候把这句注释掉）
axios.defaults.headers.post["Content-Type"] = "application/x-www-form-urlencoded";
axios.defaults.headers.post["X-Requested-With"] = "XMLHttpRequest";
axios.defaults.timeout = 10000;

function checkStatus(response) {
  return new Promise((resolve, reject) => {
    if (
      response &&
      (response.status === 200 ||
        response.status === 304 ||
        response.status === 400)
    ) {
      resolve(response.data);
    } else {
      reject({
        state: "0",
        message: "网络异常"
      });
    }
  });
}
export default {
  post(url, params) {  
    return axios({
      method: "post",
      url,
      data:params
    }).then(response => {
      return checkStatus(response);
    });
  },
  get(url, params) {
    //params = qs.stringify(params);
    return axios({
      method: "get",
      url,
      params
    }).then(response => {
      return checkStatus(response);
    });
  }
};

main.js

import Vue from 'vue'
import App from './App'
// 引入element-ui
import ElementUi from 'element-ui'

import http from './assets/js/request'     //axios封装
Vue.prototype.$http = http  

import router from './router'
Vue.use(ElementUi)

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

config/index.js

module.exports = {
  dev: {
    // Paths
    assetsSubDirectory: 'static',
    assetsPublicPath: '/',
    proxyTable: {     // 本地代理要添加proxyTable，当然在打包上传服务器的时候，要注释掉（仅限解决本地跨域测试）
     '/':{
        target:'https://baidu.com',   // 代理地址
        changeOrigin:true,
        secure:false,
        pathRewrite:{
          '^/': ''
      }
      }
    },

    // Various Dev Server settings
    host: 'localhost', // can be overwritten by process.env.HOST
    port: 8080, // can be overwritten by process.env.PORT, if port is in use, a free one will be determined
    autoOpenBrowser: false,
    errorOverlay: true,
    notifyOnErrors: true,
    poll: false, // https://webpack.js.org/configuration/dev-server/#devserver-watchoptions-

    // Use Eslint Loader?
    // If true, your code will be linted during bundling and
    // linting errors and warnings will be shown in the console.
    useEslint: true,
    // If true, eslint errors and warnings will also be shown in the error overlay
    // in the browser.
    showEslintErrorsInOverlay: false,

    /**
     * Source Maps
     */

    // https://webpack.js.org/configuration/devtool/#development
    devtool: '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#cachebusting
    cacheBusting: true,

    cssSourceMap: true
  },

  build: {
    // Template for index.html
    index: path.resolve(__dirname, '../dist/index.html'),

    // Paths
    assetsRoot: path.resolve(__dirname, '../dist'),
    assetsSubDirectory: 'static',
    assetsPublicPath: './',

    /**
     * Source Maps
     */

    productionSourceMap: false,
    // https://webpack.js.org/configuration/devtool/#production
    devtool: '#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-plugin
    productionGzip: 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
  }
}

这个只适用于解决本地接口跨域，需要设置代理的问题，顺带axios封装