In Vue, pass the backend data requested by the parent component to the child component props

 the case

Code of parent component:

Passing values ​​to child components via property binding

<template>
  <div>
        <!--首先用v-for循环把值遍历出来 ，同时通过属性绑定将父组件的值传入子组件 -->
    <Box v-for="el,index in arr"
    :title="el.title"
    :price="el.price"
    :count="el.count"
    :key="el.id"
    ></Box>
    <button>{
    
    {msg}}:{
    
    {total}}</button>
  </div>

</template>

<script>
  import Box from "@/components/myheader.vue" //引入子组件

export default {
  name: 'VueApp',

  data() {
    return {
      msg:"父组件的总价",
      arr:[] //必须提前给后端数据创建一个数据容器，不然在数据请求过来之前会出错
    };
  },
  components:{
    Box
  },
  async mounted() {
    let res=  await this.$axios("/test") //页面挂载的时候请求的后端数据
    this.arr=res.data //将后端数据保存起来
    console.log(this.arr) 
  },

  methods: {
    
  },
  computed:{
    total(){ //父组件计算总价
				return  this.arr.reduce((n1,n2)=>{
					return n1+n2.price*n2.count 
				},0)
			}
  }
};
</script>

<style scoped>

</style>

First, the data requested by the known backend is an array

 

 And how axios requests backend data

Subassembly

Child components accept via props attribute

<template>
  <div>
    菜名：{
    
    {title}}，
    数量：{
    
    {count}} <button @click="add">+</button> ,
    价格：{
    
    {price}}元
    单菜总价：{
    
    {total}}元
  </div>
</template>

<script>
export default {
  name: 'VueBox',
  props:['title','price','count'],  // 使用props属性接受父组件的值
  data() {
    
    return {
      
    };
  },

  mounted() {
    
  },
  computed:{
   total(){
    return this.count*this.price //计算单样菜品的总价
   }
  },
  methods: {
    add(){
      this.count++ //点击事件，让菜品数量增加
    }
  },
};
</script>

<style scoped>

</style>

page display

renderings

 When we click a random + button, such as clicking the first + sign

Interface changes:

 It is obvious that the total price of the menu in the child component has changed, but the total price of the parent component has not changed

Note: attribute value transfer is one-way