Vuex中的辅助函数

 

一、组件访问state

1. 从 vuex 中导入 mapState 函数

import { mapState } from 'vuex'

2. 映射为当前组件的computed计算属性：

...mapState(['count'])

3.添加到组件

<template>
  <div>
    <h1>count值：{{count}}</h1>
  </div>
</template>

<script>
import { mapState } from 'vuex'

export default {
  data() {
    return {}
  },
  computed: {
    ...mapState(['count'])
  }
}
</script>

二、触发mutations

1. 从vuex中导入mapMutations函数

import { mapMutations } from 'vuex'

2. 将指定的 mapMutations 函数，映射为当前组件的methods方法

methods: {
    ...mapMutations(['add'])
}

3.在methods使用

methods: {
   ...mapMutations(['add']),
   changeEvent(){
    this.add(5);
   }
}

三、触发actions

1. 从 vuex 中按需导入 mapActions 函数

import { mapActions } from 'vuex'

2. 在组件中添加代码

<template>
  <div class="content">
    <div>当前最新count值：{{count}}</div>
    <div>getters: {{showNum}}</div>
    <button @click="changeEvent">触发按钮</button>
   </div>
</template>

<script>
import { mapState,mapActions} from 'vuex';
export default {
  name: 'Content',
  methods: {
    ...mapActions(['addAsync']),
    // 调用dispatch触发actions时携带参数
    changeEvent2() {
      this.addAsync(5);
    },
  },
  computed: {
    ...mapState(['count']),
  }
}
</script>

四、Getters

<template>
  <div class="content">
    <img alt="Vue logo" src="../assets/logo.png">
    <div>当前最新count值：{{count}}</div>
    <div>getters: {{showNum}}</div>
    <button @click="changeEvent1">触发同步按钮</button>
    <button @click="changeEvent2">触发异步按钮</button>
  </div>
</template>

<script>
import { mapState,mapMutations, mapActions, mapGetters} from 'vuex';
export default {
  name: 'Content',
  methods: {
    ...mapMutations(['add']),
    ...mapActions(['addAsync']),
    changeEvent1(){
     this.add(5);
    },
    // 调用dispatch触发actions时携带参数
    changeEvent2() {
      this.addAsync(5);
    },
  },
  computed: {
    ...mapState(['count']),
    ...mapGetters(['showNum'])
  }
}
</script>