vue用axios时报错：Cannot read propert

import Vue from 'vue'

import Vuex from 'vuex'

import axios from 'axios'

Vue.use(Vuex)

Vue.use(axios)

报错信息：

isURLSameOrigin.js?cf95:57 Uncaught (in promise) TypeError: Cannot

read property 'protocol' of undefined

at isURLSameOrigin (eval at <anonymous> (app.js:929), <anonymous>:57:21)

at dispatchXhrRequest (eval at <anonymous> (app.js:754), <anonymous>:108:50)

at Promise (<anonymous>)

at xhrAdapter (eval at <anonymous> (app.js:754), <anonymous>:12:10)

at dispatchRequest (eval at <anonymous> (app.js:866), <anonymous>:52:10)

报错截图：

https://img1.sycdn.imooc.com/5c30712900018d9e06840122.jpg

但是，通过原型方式使用就正常：

import Vue from 'vue'

import Vuex from 'vuex'

import axios from 'axios'

Vue.use(Vuex)

Vue.prototype.$ajax = axios