//store.js
import Vue from 'vue';

export let store =Vue.observable({count:0,name:'李四'});
export let mutations={
    setCount(count){
        store.count=count;
    },
    changeName(name){
        store.name=name;
    }
}

//obserVable.vue
<template>
  <div>
    <h1>跨組件數(shù)據(jù)狀態(tài)共享 obserVable</h1>
    <div>
      <top></top>
      <bottom></bottom>
    </div>
  </div>
</template>

<script>
import  top  from './components/top.vue';
import  bottom  from './components/bottom.vue';
export default {
  name: 'obserVable',
  components: {
    top,
    bottom
  }
};
</script>

<style scoped>
</style>

//組件a
<template>
  <div class="bk">
    <span
      ><h1>a組件</h1>
      {{ count }}--{{ name }}</span
    >
    <button @click="setCount(count + 1)">當(dāng)前a組件中+1</button>
    <button @click="setCount(count - 1)">當(dāng)前a組件中-1</button>
  </div>
</template>
<script>
import { store, mutations } from '@/store';
export default {
  computed: {
    count() {
      return store.count;
    },
    name() {
      return store.name;
    }
  },
  methods: {
    setCount: mutations.setCount,
    changeName: mutations.changeName
  }
};
</script>
<style scoped>
.bk {
  background: lightpink;
}
</style>

//組件b
<template>
  <div class="bk">
    <h1>b組件</h1>
    {{ count }}--{{ name }}
    <button @click="setCount(count + 1)">當(dāng)前b組件中+1</button>
    <button @click="setCount(count - 1)">當(dāng)前b組件中-1</button>
  </div>
</template>
<script>
import { store, mutations } from '@/store';
export default {
  computed: {
    count() {
      return store.count;
    },
    name() {
      return store.name;
    }
  },
  methods: {
    setCount: mutations.setCount,
    changeName: mutations.changeName
  }
};
</script>
<style scoped>
.bk {
  background: lightgreen;
}
</style>