<template>
  <div class="xtx-numbox">
    <div class="label"><slot /></div>
    <div class="numbox">
      <a href="javascript:;" @click="handleSub(-1)">-</a>
      <input type="text" readonly :value="num" />
      <a href="javascript:;" @click="handleSub(1)">+</a>
    </div>
  </div>
</template>
<script>
// 第三方方法 useVModel 來(lái)實(shí)現(xiàn)雙向綁定
import { useVModel } from '@vueuse/core'
export default {
  name: 'XtxNumbox',
  props: {
    modelValue: {
      type: Number,
      default: 1
    }
  },
  setup(props, { emit }) {
    // useVModel 方法接收三個(gè)參數(shù)，
    // 參數(shù)一：自定義屬性 props 接收父組件傳遞過(guò)來(lái)的通過(guò) v-model 雙向綁定的數(shù)據(jù)
    // 參數(shù)二：props 里面需要傳遞的數(shù)據(jù)
    // 參數(shù)三：emit 綁定的數(shù)據(jù)需要通過(guò) emit 事件通知父組件
    const num = useVModel(props, 'modelValue', emit)
    const handleSub = n => {
      if (n < 0) {
        num.value -= 1
        if (props.modelValue === 1) {
          num.value = 1
        }
      } else {
        num.value += 1
      }
    }
    return { handleSub, num }
  }
}
</script>
<style scoped lang="less">
.xtx-numbox {
  display: flex;
  align-items: center;
  .label {
    width: 60px;
    color: #999;
    padding-left: 10px;
  }
  .numbox {
    width: 120px;
    height: 30px;
    border: 1px solid #e4e4e4;
    display: flex;
    > a {
      width: 29px;
      line-height: 28px;
      text-align: center;
      background: #f8f8f8;
      font-size: 16px;
      color: #666;
      &:first-of-type {
        border-right: 1px solid #e4e4e4;
      }
      &:last-of-type {
        border-left: 1px solid #e4e4e4;
      }
    }
    > input {
      width: 60px;
      padding: 0 5px;
      text-align: center;
      color: #666;
    }
  }
}
</style>

<XtxNumbox v-model="num">數(shù)量</XtxNumbox>