selectModule子模塊（module）有一個(gè)state值是keyword，可以通過
this.$store.state.selectModule.keyword 找到；

現(xiàn)在我想通過下面...mapState的擴(kuò)展方法來寫，要怎么寫呢？
keyword":"selectModule.keyword" 這樣寫不行,見下面代碼注釋；

select.vue

<script>
import {mapState,mapMutations,mapActions,mapGetters} from "vuex"
export default {
  name: 'app',
  data () {
    return {
    }
  },
  computed:{
    ...mapState(
        {
          //"keyword":"count"    //count可以顯示
          "keyword":"selectModule.keyword"  //selectModule.keyword 顯示不出來？？？
        }
      )
  },
  methods:{
      isShowFun:function(){
          this.$emit("isShowFun2");
      }
  },
  created:function(){
  }
}
</script>

store/index.js

import Vue from "vue"
import Vuex from "vuex"
import $ from "jquery"
Vue.use(Vuex);

var selectModule={
  state:{
    keyword:60
  },
  getters: {
    lists: function () {
      var url = "https://easy-mock.com/mock/5a61abf341d8910ea886ec50/searchLists";
      // return $.get(url,{},function(result){
      //   return result.lists;
      // })
      var result = {
        lists: [
          {
            title: "數(shù)據(jù)一"
          },
          {
            title: "數(shù)據(jù)二"
          },
          {
            title: "數(shù)據(jù)三"
          }
        ]
      }
      return result.lists;
    }
  },
    mutations:{
      changeKeyword:function(state,n){
        state.keyword=n;
      }
    },
    actions:{
      changeAction:function(context,n){
        context.commit("changeKeyword",n);
      }
    }
}

var store =new Vuex.Store({  //注意這里的Store是大寫
  state:{
    count:100,
    count2:100
  },
  mutations:{
    addIncrement:function(state,n){
      setTimeout(function(){
        state.count+=n;
      },600)
    },
    reduce:function(state,n){
      setTimeout(function(){
        state.count-=n;
      },600)
    },
    addIncrement2:function(state,n){
        state.count2+=n;
    },
    reduce2:function(state,n){
        state.count2-=n;
    }
  },
  actions:{
    addAction:function(context,n){
      setTimeout(function(){
        context.commit("addIncrement2",n);
      },600)
    },
    reduceAction:function(context,n){
      setTimeout(function(){
        context.commit("reduce2",n);
      },600)
    }
  },
  getters:{
    limitNum:function(state){
      var a=state.count>120?120:state.count;
      return a;
    },
    limitNum2:function(state){
      var a=state.count2>120?120:state.count2;
      return a;
    }
  },
  modules:{
    selectModule
  }
})

export default store