关于iview按需引用后使用this.$Modal报错的解决

import { Button， Modal } from 'iview'
Vue.component('Button', Button)
Vue.component('Modal', Modal)

<template>
    <Button @click="instance('warning')">warning</Button>
    <Button @click="instance('success')">Success</Button>
</template>

<script>
    export default {
        methods: {
            instance (type) {
                const title = 'Title';
                const content = '<p>Content of dialog</p><p>Content of dialog</p>';
                switch (type) {
                     case 'warning':
                        this.$Modal.warning({
                            title: title,
                            content: content
                        });
                        break;
                    case 'success':
                        this.$Modal.success({
                            title: title,
                            content: content
                        });
                        break;
                }
            }
        }
    }
</script>

Vue.prototype.$Modal = Modal

  <div v-if="isShow">
        <Modal v-model="addUser"  title="创建用户" >
            <add-user></add-user>
        </Modal>
    </div>

 const that = this;
 this.isShow = true;
     this.$nextTick(function () {
         that.addUser =true;
     })

const addUser =()=>import('xx.js');
components:{
        "add-user":addUser
    },

output:{chunkFilename: 'js/[name].js',}