项目场景：

<script lang="ts">
import { defineComponent, reactive, ref } from 'vue'
import { useStore } from 'vuex'
export default defineComponent({name: 'Login.vue',components: {},setup () {const onFormSubmit = (result: boolean) => {if (result) {console.log('result', result)router.push('/')const store = useStore()store.commit('login')console.log(store, useStore)}}return {    onFormSubmit}}
})
</script>

vue3组合式api中使用store.commit报错，提示：

Uncaught runtime errors:
×
ERROR
Cannot read properties of undefined (reading 'commit')
TypeError: Cannot read properties of undefined (reading 'commit')at onFormSubmit (webpack-internal:///./node_modules/ts-loader/index.js??clonedRuleSet-40.use[0]!./node_modules/vue-loader/dist/index.js??ruleSet[0].use[0]!./src/views/Login.vue?vue&type=script&lang=ts:46:23)at callWithErrorHandling (webpack-internal:///./node_modules/@vue/runtime-core/dist/runtime-core.esm-bundler.js:296:18)at callWithAsyncErrorHandling (webpack-internal:///./node_modules/@vue/runtime-core/dist/runtime-core.esm-bundler.js:304:17)at emit (webpack-internal:///./node_modules/@vue/runtime-core/dist/runtime-core.esm-bundler.js:800:5)at Object.eval (webpack-internal:///./node_modules/@vue/runtime-core/dist/runtime-core.esm-bundler.js:7528:45)at Proxy.submitForm (webpack-internal:///./node_modules/ts-loader/index.js??clonedRuleSet-40.use[0]!./node_modules/vue-loader/dist/index.js??ruleSet[0].use[0]!./src/components/ValidateForm.vue?vue&type=script&lang=ts:19:21)at eval (webpack-internal:///./node_modules/ts-loader/index.js??clonedRuleSet-40.use[0]!./node_modules/vue-loader/dist/templateLoader.js??ruleSet[1].rules[3]!./node_modules/vue-loader/dist/index.js??ruleSet[0].use[0]!./src/components/ValidateForm.vue?vue&type=template&id=36c7a62a&ts=true:24:60)at eval (webpack-internal:///./node_modules/@vue/runtime-dom/dist/runtime-dom.esm-bundler.js:1487:12)at callWithErrorHandling (webpack-internal:///./node_modules/@vue/runtime-core/dist/runtime-core.esm-bundler.js:296:18)at callWithAsyncErrorHandling (webpack-internal:///./node_modules/@vue/runtime-core/dist/runtime-core.esm-bundler.js:304:17)

打印store的值，显示undefined。

解决方法

经排查，const store = useStore()不能写在setup函数的函数内部，应该就写在setup下。useStore这个方法的调用位置是有要求的，它只能在setup函数中调用，这是它的语法规定。

import { useStore } from 'vuex'export default {setup () {const store = useStore()const onFormSubmit = (result: boolean) => {if (result) {store.commit('login')console.log(store, useStore)}}return {    onFormSubmit}}
}

组合式API中使用vuex文档：官网