Vue组件通信之父传子与子传父详细讲解

<script setup>
const props = defineProps(['foo'])
console.log(props.foo)
</script>

export default {
  props: ['foo'],
  setup(props) {
    // setup() 接收 props 作为第一个参数
    console.log(props.foo)
  }
}

<template>
	<show-info name="kk" age="18" height="1.7"  />
</template>

 export default {
        props:{
            name :{
                type:String,
                default:"我是默认值name"
            },
            height:{
                type:Number,
                default:2
            }
        }
    }

defineProps({
  title: String,
  likes: Number
})

export default {
  props: {
    title: String,
    likes: Number
  }
}

<template>
    <div class="app">
    <h2>当前计数：{{counter}}</h2>
    <!-- 1.自定义add-counter 并且监听内部的add事件 -->
   <add-counter @add="addBtnClick"></add-counter>  
   <!-- 2.自定义su-counter组件，监听内部的sub事件 -->
   <sub-counter @sub="subBtnClick"></sub-counter>
   </div>
</template>
<script>
import AddCounter from './AddCounter.vue'
import SubCounter from './SubCounter.vue'
    export default {
  components: { 
    AddCounter,
    SubCounter
 },
    data() {
        return {
            counter:0
        }
    },
    methods:{
        addBtnClick(count) {
            this.counter += count
        },
        subBtnClick(count) {
            this.counter -= count
        }
    }
}
</script>

<template>
    <div class="add">
        <button @click="btnClick(1)">+1</button>
        <button @click="btnClick(5)">+5</button>
        <button @click="btnClick(10)">+10</button>
    </div>
</template>
<script>
    export default {
        methods:{
            btnClick(count) {
                // 让子组件发出去一个自定义事件
                // 第一个参数自定义的事件名称，第二个参数是传递的参数
                this.$emit("add",count)
            }
        }
    }
</script>

<template>
    <div class="sub">
        <button @click="btnClick(1)">-1</button>
        <button @click="btnClick(5)">-5</button>
        <button @click="btnClick(10)">-10</button>
    </div>
</template>
<script>
    export default {
        // 1.emits数组语法
       emits:["addd"],
       methods:{
        btnClick(count) {
            this.$emit("sub",count)
        }
       }
    }
</script>