vue：vuex中mapState、mapGetters、mapActions辅助函数及Module的使用

import Vue from ‘vue‘;
import Vuex from ‘vuex‘;
Vue.use(Vuex);

const state={//要设置的全局访问的state对象
  showFooter: true,
  changableNum:0
  count: 0
  //要设置的初始属性值
};

const getters = {   //实时监听state值的变化(最新状态)
  isShow(state) {  //方法名随意,主要是来承载变化的showFooter的值
    return state.showFooter
  },
  getChangedNum(){  //方法名随意,主要是用来承载变化的changableNum的值
    return state.changebleNum
  }
};

const mutations = {
  show(state) {   //自定义改变state初始值的方法，这里面的参数除了state之外还可以再传额外的参数(变量或对象);
    state.showFooter = true;
  },
  hide(state) {  //同上
    state.showFooter = false;
  },
  newNum(state,sum){ //同上，这里面的参数除了state之外还传了需要增加的值sum
    state.changableNum+=sum;
  }
};

const actions = {
  hideFooter(context) {  //自定义触发mutations里函数的方法，context与store 实例具有相同方法和属性
    context.commit(‘hide‘);
  },
  showFooter(context) {  //同上注释
    context.commit(‘show‘);
  },
  getNewNum(context,num){   //同上注释，num为要变化的形参
    context.commit(‘newNum‘,num)
  }
};

const store = new Vuex.Store({
  state,
  getters,
  mutations
});

export default store;

// The Vue build version to load with the `import` command
// (runtime-only or standalone) has been set in webpack.base.conf with an alias.
import Vue from ‘vue‘
import ElementUI from ‘element-ui‘
import ‘element-ui/lib/theme-chalk/index.css‘
import App from ‘./App‘
import router from ‘./router/router.js‘
import store from ‘./store‘
import echarts from ‘echarts‘

Vue.config.productionTip = false
Vue.use(ElementUI)
Vue.use(echarts)
Vue.prototype.$echarts = echarts

/* eslint-disable no-new */
new Vue({
  el: ‘#app‘,
  router,
  store,
  components: { App },
  template: ‘<App/>‘
})

<template>
 <div>
  <h3>Count is {{某属性}}</h3>
 </div>
</template>
<script>
 export default {
  computed: {
   count () {
    return this.$store.state.某属性
   }
  }
 }
</script>

<script>
 import {mapState} from "vuex"; // 引入mapState 
 export default {
　　// 下面这三种写法都可以
  computed: mapState({
   // 箭头函数可使代码更简练
    count: state => state.count,

    // 传字符串参数 ‘count‘ 等同于 `state => state.count`
    countAlias: ‘count‘,

    // 为了能够使用 `this` 获取局部状态，必须使用常规函数
    countPlusLocalState (state) {
      return state.count + this.localCount
    }
  })
 }
</script>

<script>
 import {mapState} from "vuex";
 
 export default {
  computed: mapState([ // 数组
   "count"
  ])
 }
</script>

<script>
 import {mapState} from "vuex";
 
 export default {
  computed: {
       ...mapState([
           "count"
       ]),
       getValue(){
           return 1;
        }
    }
 }
</script>

//collection.js

const state={
  collects:[‘hi‘],  //初始化一个colects数组
  field: ‘空天作战任务规划‘
};

const getters={

};

const mutations={

};

const actions={

};

export default {
  namespaced:true,//用于在全局引用此文件里的方法时标识这一个的文件名
  state,
  getters,
  mutations,
  actions
}

//footerStatus.js

const state={   //要设置的全局访问的state对象
  name: ‘beautiful‘,
  address: ‘Hunan Changsha‘,
  school: ‘国防科大‘,
  showFooter: true,
  changableNum:0
  //要设置的初始属性值
};

const getters = {   //实时监听state值的变化(最新状态)

};

const mutations = {
  changeSchool(state, value){
    state.school = value;
  }
};

const actions = {
  _changeSchool(context, value){
    context.commit(‘changeSchool‘, value)
  }
};

export default {
  namespaced: true, //用于在全局引用此文里的方法时标识这一个的文件名
  state,
  getters,
  mutations,
  actions
}

import Vue from ‘vue‘
import Vuex from ‘vuex‘
import collection from ‘./modules/collection‘
import footerStatus from ‘./modules/footerStatus‘

Vue.use(Vuex)

export default new Vuex.Store({
  modules: {
    collection,
    footerStatus
  }
})

<template>
  <div>
    <p>name: {{name}}</p>
    <p>school: {{school}}</p>
    <p>address: {{address}}</p>
    <p>field: {{field}}</p>
    <p>arrList: {{arrList}}</p>
    <div><button @click="changeSchool()">改变值</button></div>
  </div>
</template>

<script>
  import {mapState, mapGetters} from ‘vuex‘
  export default {
    data(){
      return {
        use: ‘vuex高级使用方法‘
      }
    },
    computed: {
      ...mapState({
        name: state => state.footerStatus.name,
        address(state){
          return state.footerStatus.address;
        }
      }),
      ...mapState(‘footerStatus‘, {
        school: ‘school‘
      }),
      ...mapState(‘collection‘, [‘field‘]),
      _use(){
        this.use;
      },
      ...mapGetters(‘collection‘, {
        arrList: ‘renderCollects‘
      })
    },
    methods: {
      changeSchool(){
        this.$store.dispatch("footerStatus/_changeSchool", ‘北大‘);
      }
    }
  }
</script>

<style scoped>

</style>