在vue3中使用vuex

. 下载安装 cnpm install vuex -S ;本次下载的版本是 "vuex": "^4.0.2"

2.创建store/index.js

import { createStore } from 'vuex'
import http from '@/utils/http.js'
// Create a new store instance.
const store = createStore({
  state () {
    return {
      count: 0,
      user:{}
    }
  },
  mutations: {
    increment (state,num) {
      state.count += num;
    },
    setUser(state,user){
        state.user = user;
    }
  },
  actions:{
      getUserInfo(context,params){
        return new Promise((resolve,reject)=>{
            http.get("/pyapi/test/user",params).then(res=>{
                if(res.status == 200){
                    context.commit("setUser",res.result)
                    resolve(res.result)
                }else{
                    reject({})
                }

            }).catch(e=>{
                reject(e)
            })
        })
      }
  }
})
export default store

3. 在main.js中

import store from './store/index.js'

const App = createApp(App)

app.use(store)

4.在组件中使用

<template>
  <div class="test">
      <p>count:{{ count }}  <el-button @click="addCount">+2</el-button></p>
  </div>
    <div class="user">
      <el-button @click="getUserInfo">getUserInfo</el-button>
      <ul>
        <li>name: {{user.name}}</li>
        <li>age: {{user.age}}</li>
      </ul>
  </div>
</template>

<script>
 
import $store from '@/store/index.js'
import { computed } from 'vue';
export default {
  name: "testCom",
  setup() {
    let count = computed(()=>{
      return $store.state.count
    })

    const addCount = ()=>{
      $store.commit('increment',2) // 同步
    }
    let user = computed(()=>{
      return $store.state.user
    })

    const getUserInfo = ()=>{
       $store.dispatch('getUserInfo', {id:111}); // 异步
    }

    return {
      count,
      addCount,
      user,
      getUserInfo
    };
  },
};
</script>

<style scoped>
</style>