const store = new Vuex.Store({
  state: {
    count: 0,
  },
  mutations: {
    increment(state, n = 1) {
      state.count += n;
    }
  },
  actions: {
    asyncInrement(context) {
      return new Promise(resolve => {
        setTimeout(() => {
          context.commit('increment');
          resolve();
        }, 1000)
      });
    }
  }
});

<template>

  <div>
    {{count}}
    <button @click="asyncIncrementByAction">+1</button>
  </div>
</template>

<script>
  export default {
    name: "index.vue",
    computed: {
      count() {
        return this.$store.state.count;
      }
    },
    methods: {
      asyncIncrementByAction() {
        this.$store.dispatch('asyncInrement').then(() => {
          console.log(this.$store.state.count);
        })
      }
    }
  }
</script>

const store = new Vuex.Store({
...
  actions: {
   ...
    asyncInrement2(context, callback) {
      setTimeout(() => {
        context.commit('increment');
        callback();
      }, 1000);
    }
  }
});

<template>
  <div>
    ...
    {{count}}
    <button @click="asyncIncrementByAction2">+1(Callback)</button>
  </div>
</template>

<script>
  export default {
    ...
    methods: {
      ...
      asyncIncrementByAction2() {
        this.$store.dispatch('asyncInrement2',() => {
          console.log(this.$store.state.count);
        });
      }
    }
  }
</script>

npm install vuex --save

/**
 * 创建完文件后需要去到main.js中引入成全局
 */
import Vue from "vue";
import Vuex from "vuex";
//使用vuex
Vue.use(Vuex);
const state = {
 targetUser: {} //用户详细资料数据
};
 
const getters = {
 //获取到用户状态,//实时监听state值的变化(最新状态)
 targetUser: state => state.targetUser
};
 
const mutations = {
 //自定义改变state初始值的方法
 SET_TARGET_USER(state, targetUser) {
  if (targetUser) {
   state.targetUser = targetUser; //如果targetUser有内容就赋给状态信息
  } else {
   //如果没内容就给targetUser赋空对象
   state.targetUser = {};
  }
 }
};
 
const actions = {
 //这里面的方法是用来异步触发mutations里面的方法,context与store 实例具有相同方法和属性
 // 页面定义的setGargetUser,targetUser为页面传过来的值
 setGargetUser({ commit }, targetUser) {
  commit("SET_TARGET_USER", targetUser);
 }
};

this.$store.dispatch('setGargetUser',friend)

 computed:{
    // 提示vuex中存入的用户详细资料
    targetUser(){
      return this.$store.getters.targetUser
    }
   },

this.$store.dispatch('setUser',decode)

/**
 * 创建完文件后需要去到main.js中引入成全局
 */
import Vue from "vue";
import Vuex from "vuex";
// 持久存储插件
import createPersistedState from "vuex-persistedstate";
 
//使用vuex
Vue.use(Vuex);
 
/**
 * 在需要多人协作的项目中，我们可以使用常量代替mutation 事件类型。这在各种 Flux 实现中是很常见的模式。同时把这些常量放在单独的文件中可以让协作开发变得清晰。
 * 定义存储信息
 *
 *  */
 
const types = {
 SET_TARGET_USER: "SET_TARGET_USER" //详细资料
};
 
const state = {
 //用户初始化的状态
 targetUser: {} //用户详细资料数据
};
const getters = {
 //获取到用户状态,//实时监听state值的变化(最新状态)
 targetUser: state => state.targetUser
};
const mutations = {
 //自定义改变state初始值的方法
 
 [types.SET_TARGET_USER](state, targetUser) {
  if (targetUser) {
   state.targetUser = targetUser; //如果targetUser有内容就赋给状态信息
  } else {
   //如果没内容就给targetUser赋空对象
   state.targetUser = {};
  }
 }
};
 
const actions = {
 //这里面的方法是用来异步触发mutations里面的方法,context与store 实例具有相同方法和属性
 setGargetUser({ commit }, targetUser) {
  commit(types.SET_TARGET_USER, targetUser);
  // localStorage.setItem("SET_TARGET_USER", JSON.stringify(targetUser));
 }
};
export default new Vuex.Store({
 state,
 mutations,
 getters,
 actions,
});

this.$store.getters.targetUser