vue3中getCurrentInstance怎么使用

<template>
  <!-- 父组件 -->
  <div>
    <!-- 子组件 -->
    <Child ref="child" />
    <button @click="changeChildren">子组件count+1</button>
  </div>
</template>
 
<script setup lang="ts" name="Father">
import { getCurrentInstance, ComponetInternalInstance,ref } from "vue";
import Child from "./zi.vue";
const child = ref(null)
 // as ComponetInternalInstance表示类型断言，ts时使用。否则报错，proxy为null
const { proxy } = getCurrentInstance() as ComponetInternalInstance;
function changeChildren() {
  proxy.$refs.child.count += 1;
  //也可以使用ref数据.value的形式调用：
  //child.value.count += 1
  console.log(child.value.name)
}
</script>
 
<style scoped></style>

import api from "./utils/api.js"
import StringUtil from "./utils/StringUtil.js"

app.config.globalProperties.api = api;
app.config.globalProperties.StringUtil = StringUtil;

import {getCurrentInstance } from 'vue';

const { proxy } = getCurrentInstance();

console.log(proxy.api);
console.log(proxy.StringUtil.isBlank('1'));

<template>
  <div>

  </div>
</template>
<script>
import { defineComponent, getCurrentInstance } from 'vue'

export default defineComponent({
  name: 'About',
  setup(){
    const { proxy } = getCurrentInstance()
    console.log(proxy.$root.$route)
    console.log(proxy.$root.$router)
    return {}
  }
})
</script>

import { defineComponent } from ‘vue'
import { useRoute, useRouter } from ‘vue-router'
export default defineComponent({
setup () {
const $route = useRoute()
const r o u t e r = u s e R o u t e r ( ) c o n s o l e . l o g ( router = useRouter() console.log(router=useRouter()console.log(route)
console.log($router)
}
})

const instance = getCurrentInstance()
console.log(instance.appContext.config.globalProperties)

const { proxy } = getCurrentInstance()