vue父子組件傳值過(guò)程：
子組件：props接收,data里同步數(shù)據(jù)
父組件：在子組件通過(guò)$emit()發(fā)送什往，父組件定義事件接收

示例代碼：
index.vue

<template>
  <div class="container" @click="clickHandle">
    <div class="message">{{msg}}</div>
    <!-- :init-num='10' @clicknum="handleClickNum"  父子組件傳值 -->
    <click-counter :init-num="10" @clicknum="handleClickNum"/>
  </div>
</template>

<script>
import ClickCounter from "@/components/click-counter";
export default {
  components:{ClickCounter},

  data () {
    return {
      msg: 'Hello'
    }
  },

  methods: {
    clickHandle () {
      this.msg = 'Clicked!!!!!!'
    },
    handleClickNum(data){
        console.log('>>>',data.num)
    }
  }
}
</script>

<style scoped>
.message {
  color: red;
  padding: 10px;
  text-align: center;
}
</style>

click-counter.vue

<template>
  <div class="click-counter">
    <div class="counter-num">次數(shù)：{{num}}</div>
    <button class="counter-btn" @click="handleClick">點(diǎn)我呀戈次！</button>
    <button class="counter-reset-btn" @click="handleResetClick">清零</button>
  </div>
</template>
<script>
export default {
  props:{
    initNum:{
      type:Number,
      default:0
    }
  },
  data() {
    return {
      num: this.initNum
    };
  },
  methods: {
    handleClick() {
      this.num += 1;
      this.notifyNum();
    },
    handleResetClick() {
      this.num = 0;
      this.notifyNum();
    },
    notifyNum(){
      this.$emit('clicknum',{
        num:this.num
      })
    }
  }
};
</script>
<style>
.click-counter {
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid red;
  background-color: #ffffff;
  padding: 10px;
}
.counter-num,
.counter-btn,
.counter-reset-btn {
  flex: 1;
  margin: 3px;
}
</style>

插槽：在組件里單獨(dú)出來(lái)一個(gè)塊，用來(lái)寫(xiě)入引入組件時(shí)添加的其他元素型宙，在父組件中可穿可不傳

 <!-- :init-num='10' @clicknum="handleClickNum"  父子組件傳值 -->
    <click-counter :init-num="10" @clicknum="handleClickNum">
        <input type="checkbox"> 插槽
    </click-counter>

<template>
  <div class="click-counter">
    <div class="counter-num">次數(shù)：{{num}}</div>
    <button class="counter-btn" @click="handleClick">點(diǎn)我呀响牛！</button>
    <button class="counter-reset-btn" @click="handleResetClick">清零</button>
    <slot><slot/>
  </div>
</template>