代碼import Vue from 'vue'import App from './App'import router from './router'import common from './assets/js/common'import Vuex from 'vuex'import ElementUi from 'element-ui'import 'element-ui/lib/theme-default/index.css'import MintUi from 'mint-ui'import 'mint-ui/lib/style.css'Vue.config.productionTip = falseVue.use(common)Vue.use(ElementUi)Vue.use(MintUi)Vue.use(Vuex)const vuex_store = new Vuex.store({state:{     msg:""}, mutations:{     showUserName(state){         alert(state.msg);     } }})new Vue({el: '#app',store:vuex_store,router,template: '<App/>',components: { App }})報錯如下Uncaught TypeError: __WEBPACK_IMPORTED_MODULE_4_vuex__.a.store is not a function