vue中的provide/inject的学习使用

<template>
 <div>
<childOne></childOne>
 </div>
</template>

<script>
 import childOne from '../components/test/ChildOne'
 export default {
  name: "Parent",
  provide: {
   for: "demo"
  },
  components:{
   childOne
  }
 }

<template>
 <div>
  {{demo}}
  <childtwo></childtwo>
 </div>
</template>

<script>
 import childtwo from './ChildTwo'
 export default {
  name: "childOne",
  inject: ['for'],
  data() {
   return {
    demo: this.for
   }
  },
  components: {
   childtwo
  }
 }
</script>

<template>
 <div>
  {{demo}}
 </div>
</template>

<script>
 export default {
  name: "",
  inject: ['for'],
  data() {
   return {
    demo: this.for
   }
  }
 }
</script>