《进阶篇第9章》学习vuex知识点后练习：把求和案例改成多组件共享数据

incrementOdd(){
	if(this.sum % 2){
		this.sum += this.n
	}
}

<h1>当前求和为：{{sum}}</h1>
<select v-model="n">
	<option value="1">1</option>
	<option value="2">2</option>
	<option value="3">3</option>
</select>

<h1>当前求和为：{{sum}}</h1>
<select v-model="n">
	<option :value="1">1</option>
	<option :value="2">2</option>
	<option :value="3">3</option>
</select>

<h1>当前求和为：{{sum}}</h1>
<select v-model.number="n">
	<option value="1">1</option>
	<option value="2">2</option>
	<option value="3">3</option>
</select>

//引入Vue
import Vue from 'vue'
//引入App
import App from './App.vue'
//引入插件
import vueResource from 'vue-resource'
//引入store
import store from './store'

//关闭Vue的生产提示
Vue.config.productionTip = false
//使用插件
Vue.use(vueResource)

//创建vm
new Vue({
	el:'#app',
	render: h => h(App),
	store,
	beforeCreate() {
		Vue.prototype.$bus = this
	}
})

<template>
  <div>
    <Count/>
    <hr>
    <Person/>
  </div>
</template>

<script>
import Count from './components/Count'
import Person from './components/Person'

export default {
  name:'App',
  components:{Count,Person},
  mounted() {
    // console.log('App',this)
  },
}
</script>

<template>
  <div>
    <h1>当前求和为：{{sum}}</h1>
    <h3>当前求和放大10倍为：{{bigSum}}</h3>
    <h3>我在{{school}}，学习{{subject}}</h3>
    <h3 style="color:red">Person组件的总人数是：{{personList.length}}</h3>
    <select v-model.number="n">
      <option value="1">1</option>
      <option value="2">2</option>
      <option value="3">3</option>
    </select>
    <button @click="increment(n)">+</button>
    <button @click="decrement(n)">-</button>
    <button @click="incrementOdd(n)">当前求和为奇数再加</button>
    <button @click="incrementWait(n)">等一等再加</button>
  </div>
</template>

<script>
import {mapState,mapGetters,mapMutations,mapActions} from 'vuex'
export default {
  name:'Count',
  data() {
    return {
      n:1, //用户选择的数字
    }
  },
  computed:{
    //借助mapState生成计算属性，从state中读取数据。（数组写法）
    ...mapState(['sum','school','subject','personList']),
    //借助mapGetters生成计算属性，从getters中读取数据。（数组写法）
    ...mapGetters(['bigSum'])
  },
  methods: {
    //借助mapMutations生成对应的方法，方法中会调用commit去联系mutations(对象写法)
    ...mapMutations({increment:'JIA',decrement:'JIAN'}),
    //借助mapActions生成对应的方法，方法中会调用dispatch去联系actions(对象写法)
    ...mapActions({incrementOdd:'jiaOdd',incrementWait:'jiaWait'})
  },
  mounted() {
    // const x = mapState({he:'sum',xuexiao:'school',xueke:'subject'})
    // console.log(x)
  },
}
</script>

<style lang="css">
button{
  margin-left: 5px;
}
</style>

<template>
	<div>
		<h1>人员列表</h1>
		<h3 style="color:red">Count组件求和为：{{sum}}</h3>
		<input type="text" placeholder="请输入名字" v-model="name">
		<button @click="add">添加</button>
		<ul>
			<li v-for="p in personList" :key="p.id">{{p.name}}</li>
		</ul>
	</div>
</template>

<script>
	import {nanoid} from 'nanoid'
	export default {
		name:'Person',
		data() {
			return {
				name:''
			}
		},
		computed:{
			personList(){
				return this.$store.state.personList
			},
			sum(){
				return this.$store.state.sum
			}
		},
		methods: {
			add(){
				const personObj = {id:nanoid(),name:this.name}
				this.$store.commit('ADD_PERSON',personObj)
				this.name = ''
			}
		},
	}
</script>

//该文件用于创建Vuex中最为核心的store
import Vue from 'vue'
//引入Vuex
import Vuex from 'vuex'
//应用Vuex插件
Vue.use(Vuex)

//准备actions——用于响应组件中的动作
const actions = {
    /* jia(context,value){
        console.log('actions中的jia被调用了')
        context.commit('JIA',value)
    },
    jian(context,value){
        console.log('actions中的jian被调用了')
        context.commit('JIAN',value)
    }, */
    jiaOdd(context,value){
        console.log('actions中的jiaOdd被调用了')
        if(context.state.sum % 2){
            context.commit('JIA',value)
        }
    },
    jiaWait(context,value){
        console.log('actions中的jiaWait被调用了')
        setTimeout(()=>{
            context.commit('JIA',value)
        },500)
    }
}
//准备mutations——用于操作数据（state）
const mutations = {
    JIA(state,value){
        console.log('mutations中的JIA被调用了')
        state.sum += value
    },
    JIAN(state,value){
        console.log('mutations中的JIAN被调用了')
        state.sum -= value
    },
    ADD_PERSON(state,value){
        console.log('mutations中的ADD_PERSON被调用了')
        state.personList.unshift(value)
    }
}
//准备state——用于存储数据
const state = {
    sum:0, //当前的和
    school:'尚硅谷',
    subject:'前端',
    personList:[
        {id:'001',name:'张三'}
    ]
}
//准备getters——用于将state中的数据进行加工
const getters = {
    bigSum(state){
        return state.sum*10
    }
}

//创建并暴露store
export default new Vuex.Store({
    actions,
    mutations,
    state,
    getters
})