使用vuex的state狀態對象的5種方式

//state.js
const state = {
 headerBgOpacity:0,
 loginStatus:0,
 count:66
}
export default state
//index.js
import Vue from 'vue'
import Vuex from 'vuex'
import state from './state'
import actions from './actions'
import getters from './getters'
import mutations from './mutations'
Vue.use(Vuex)
export default new Vuex.Store({
 state,
 actions,
 getters,
 mutations
})

<template>
 <div class="test">
 {{$store.state.count}} <!--第一種方式-->
 </div>
</template>
<script type="text/ecmascript-6">
 export default{
 name:'test',
 data(){
 return{ }
 }
 }
</script>
<style>
</style>

<template>
 <div class="test">
 {{count}} <!--步驟二-->
 </div>
</template>
<script type="text/ecmascript-6">
 export default{
 name:'test',
 data(){
 return{}
 },
 computed:{
 count(){
 return this.$store.state.count; //步驟一
 }
 }
 }
</script>
<style>
</style>

<template>
 <div class="test">
 {{count}} <!--步驟三-->
 </div>
</template>
<script type="text/ecmascript-6">
 import {mapState} from 'vuex' //步驟一
 export default{
 name:'test',
 data(){
 return{}
 },
 computed:mapState({ //步驟二,對象方式
 count:state => state.count
 })
 }
</script>
<style>
</style>

<template>
 <div class="test">
 {{count}} <!--步驟三-->
 </div>
</template>
<script type="text/ecmascript-6">
 import {mapState} from 'vuex' //步驟一
 export default{
 name:'test',
 data(){
 return{}
 },
 computed:mapState([ //步驟二,數組方式
 "count"
 ])
 }
</script>
<style>
</style>

<template>
 <div class="test">
 {{count}} <!--步驟三-->
 </div>
</template>
<script type="text/ecmascript-6">
 import {mapState} from 'vuex' //步驟一
 export default{
 name:'test',
 data(){
 return{}
 },
 computed:{
 ...mapState([ //步驟二，三個點方式
 "count"
 ])
 }
 }
</script>
<style>
</style>