今天要來學習 Vue 中的 event，使用的是 v-on，可簡解為 @

一個簡單內聯事件的例子

<template>
  <div :class="attr">
    <p>Count is: {{ count }}</p>
    <button @click="count++">Add 1</button>
    
  </div>
</template>

<script setup>
import { ref } from 'vue'
const attr = 'box'
const count = ref(0)

</script>

<style scoped>
    .box{
        text-align: center;
        display: flex;
        flex-direction: column;
        justify-content: center;
        font-size: x-large;
        border: solid;
        margin-left: 650px;
        margin-top: 5px;
        height: 200px;
        width:350px;
        padding: 35px;
    }
</style>

按下按鈕後可使 count+1

也可以將 v-on 綁定一個 function，再定義 function 要做的事情

<template>
  <div :class="attr">
    <button @click="greet">Greet</button>
    
  </div>
</template>

<script setup>
import { ref } from 'vue'
const attr = 'box'
const name = ref('Vue.js')

function greet(event) {
  alert(`Hello ${name.value}!`)
  if (event) {
    alert(event.target.tagName)
  }
}

</script>

<style scoped>
    .box{
        text-align: center;
        display: flex;
        flex-direction: column;
        justify-content: center;
        font-size: x-large;
        border: solid;
        margin-left: 650px;
        margin-top: 5px;
        height: 200px;
        width:350px;
        padding: 35px;
    }
</style>

透過 event.target.tagName 訪問觸發事件的元素