一、main.ts中定义

二、在页面中应用

<template>  <div>    全局变量    <div>办法1(应用 getCurrentInstance 的 appContext):{{way1}}</div>    <div>办法2(从 getCurrentInstance 构造出 proxy):{{way2}}</div>  </div></template><script lang="ts">import { defineComponent, getCurrentInstance, onMounted,reactive,toRefs} from 'vue';export default defineComponent({  name:'board',  setup() {    const { proxy } = getCurrentInstance() as any;    const data = reactive({      way1:  getCurrentInstance()?.appContext.config.globalProperties.$message,      way2: proxy.$message,    })        onMounted(()=>{      // 打印      console.log(data.way1,'办法1')      console.log(data.way2,'办法2')    })        return {      ...toRefs(data),    }  },})</script><style scoped lang="less"></style>

打印后果:

页面展现: