Some components will report errors or fail to display after iview packaging, but everything is fine before packaging.

iview, is used in the UI library of the project. Everything is fine before npm run build, but after packaging, there will be problems such as calling this.$Message error, Modal,Slider,Checkbox and other tools can not be displayed. What is the reason?
this is the error report of calling method:

main.js:

import "babel-polyfill"
import "./assets/css/reset.styl"
import "./assets/css/theme-default.styl"
import Vue from "vue"
import Vuex from "vuex"
import App from "./App"
import {
  i18n
} from "@/locale"
import store from "@/store"
import router from "./router"
import axios from "@/apis/http/axios.js"
import commonHttp from "@/apis/http/commonHttp"
import _P from "@/assets/js/public"
import HappyScroll from "vue-happy-scroll"
import iView from "iview";
import "iview/dist/styles/iview.css";
import {Message,Spin,Page,Switch,Upload,Select,Slider,CheckboxGroup,Modal,Checkbox} from "iview";

import "vue-happy-scroll/docs/happy-scroll.css";

Vue.config.productionTip = false
Vue.use(Vuex)
Vue.use(_P)
Vue.use(HappyScroll)
Vue.use(iView)
Vue.prototype.axios = axios
Vue.prototype.commonHttp = commonHttp
Vue.prototype.$Message = Message
Vue.prototype.$Spin = Spin
Vue.prototype.$Page = Page
Vue.prototype.$Switch = Switch
Vue.prototype.$Upload = Upload
Vue.prototype.$Select = Select
Vue.prototype.$Slider = Slider
Vue.prototype.$CheckboxGroup = CheckboxGroup
Vue.prototype.$Modal = Modal
Vue.prototype.$Checkbox = Checkbox


/* eslint-disable no-new */
new Vue({
  el: "-sharpapp",
  router,
  i18n,
  store,
  template: "<App/>",
  components: {
    App
  }
})

In the

vue component, I called directly without introducing a module. The direct npm run dev is displayed normally. I suspect it is a plug-in conflict and other problems. To solve the problem

// import iView from 'iview'; // Message Spin vue this.$Message import {Message,Spin,Page,Switch,Upload,Select,Slider,CheckboxGroup,Modal,Checkbox} from 'iview'; Vue.prototype.$Message = Message Vue.prototype.$Spin = Spin Vue.prototype.$Page = Page Vue.prototype.$Switch = Switch Vue.prototype.$Upload = Upload Vue.prototype.$Select = Select Vue.prototype.$Slider = Slider Vue.prototype.$CheckboxGroup = CheckboxGroup Vue.prototype.$Modal = Modal Vue.prototype.$Checkbox = Checkbox