vue3---getCurrentInstance

父组件中：

1.setup语法糖中导入子组件
2.在子组件标签上绑定ref值
3.setup内部从vue中按需导出 getCurrentInstance 方法
4.调用getCurrentInstance方法导出proxy
5.通过proxy.$refs.子组件ref名.子组件内属性/方法 实现调用

<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nullconst{ proxy }=getCurrentInstance()as ComponetInternalInstance;functionchangeChildren(){
  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>

main.js

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'));

方式一、通过 getCurrentInstance 方法获取当前组件实例，从而获取 route 和 router

Html

<template><div></div></template><script>import{ defineComponent, getCurrentInstance }from'vue'exportdefaultdefineComponent({name:'About',setup(){const{ proxy }=getCurrentInstance()
    console.log(proxy.$root.$route)
    console.log(proxy.$root.$router)return{}}})</script>

方式二：通过从路由中导入 useRoute useRouter 使用 route 和 router。 官方Api
Html

import { defineComponent } from ‘vue’
import { useRoute, useRouter } from ‘vue-router’
export default defineComponent({
setup () {
const $route = useRoute()
const

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    router = useRouter() console.log( 
   
  
router=useRouter()console.log(route)

console.log($router)
}
})