useRouter肯定要放在setup办法内的顶层,否则作用域扭转useRouter()执行返回的是undefined。

正确应用

<script setup>import { useRouter } from 'vue-router';const router = useRouter();const toLogin = () => {    router.push({ name: 'login' });};</script>

谬误应用

<script setup>import { useRouter } from 'vue-router';const toLogin = () => {    const router = useRouter(); //router为 undefine    router.push({ name: 'login' });};</script>