$parent 和 $children的用法

$parent

baseSon.vue

<template>
    <div style="background-color: #999">
        <h2>儿子金钱:{{ sonMoney }}</h2>
        <button @click="giveFatherMoney(100)">给父亲100</button>
        <button @click="subFatherMoney(5)">拿走父亲5块钱</button>
    </div>
</template>
   
<script>
export default {
    name: "baseSon",
    props: ["fatherMoney"],
    data() {
        return {
            sonMoney: 200,
        };
    },
    methods: {
        //   giveFatherMoney(money) {
        //     this.$parent.fatherMoney += money;
        //     this.sonMoney -= money;
        //   },
        giveFatherMoney (money) {
            this.$parent.changeFatherMoney(money)
        },
        subFatherMoney (money) {
            this.$parent.fatherMoney -= money
        }
    },
};
</script>
   
<style></style>

App.vue

<template>
    <div class="app">
        父亲的钱：{{ fatherMoney }}
        <baseSon></baseSon>
        <baseDau></baseDau>
    </div>
</template>

<script>
import baseSon from './components/baseSon.vue';
import baseDau from './components/baseDau.vue';
export default {
    components:{
        baseSon,baseDau
    },
    data(){
        return {
            fatherMoney:10000
        }
    },
    methods:{
        changeFatherMoney(money){
            this.fatherMoney += money
        }
       
    }
}

</script>
   
<style></style>

childern 不好用，所以建议$ref

ref

App.vue

<template>
    <div class="app">
        父亲的钱：{{ fatherMoney }}
        <button @click="getSonMoney(50)">父亲拿走儿的50元</button>
        <button @click="giveSonMoney(100)">父亲给儿的100元</button>
        <baseSon ref="baseSonRef" ></baseSon>
        
    </div>
</template>

<script>
import baseSon from './components/baseSon.vue';

export default {
    components:{
        baseSon
    },
    data(){
        return {
            fatherMoney:10000
        }
    },
    methods:{
        changeFatherMoney(money){
            this.fatherMoney += money
        },
        getSonMoney(money){
            console.log('getSonMoney');
            
            // this.$children.sonMoney -= money
            this.$refs.baseSonRef.sonMoney -= money
            // console.log('this.$children.sonMoney', this.$children.sonMoney);
            
        },
        giveSonMoney(money){
            this.$refs.baseSonRef.changeSonMoney(money)
            // this.$children.changeSonMoney(money)
        }
    }
}

</script>
   
<style></style>

baseSon.vue

<template>
    <div style="background-color: #999">
        <h2>儿子金钱:{{ sonMoney }}</h2>
        <button @click="giveFatherMoney(100)">给父亲100</button>
        <button @click="subFatherMoney(5)">拿走父亲5块钱</button>
    </div>
</template>
   
<script>
export default {
    name: "baseSon",
    props: ["fatherMoney"],
    data() {
        return {
            sonMoney: 200,
        };
    },
    methods: {
        //   giveFatherMoney(money) {
        //     this.$parent.fatherMoney += money;
        //     this.sonMoney -= money;
        //   },
        giveFatherMoney(money) {
            this.$parent.changeFatherMoney(money)
        },
        subFatherMoney(money) {
            this.$parent.fatherMoney -= money
        },
        changeSonMoney(money) {
            this.sonMoney += money
        }
    },
};
</script>
   
<style></style>