vue 3 实现 购物车增加 减少按钮（2）

html

<template>
  <div class="mall-input-number">
      <span class="reduce" @click="() => handleChange(null,-1)">-</span>
    <input
      type="text"
      class="text"
      :value="value"
      min="1"
      @input="(e) => handleChange(e.target, 0)"
    />
    <span class="increase" @click="() => handleChange(null, 1)">+</span>
  </div>
</template>

js

<script lang="ts">
import {
    
     defineComponent } from 'vue';

export default defineComponent({
    
    
    name: 'MallInputNumber',
    props: {
    
    
        value: {
    
    
            type: Number,
            required: true,
        },
    },
    setup(props, ctx) {
    
    
        // 更改购物车商品数量
        const handleChange = (e: HTMLInputElement | null, value: number) => {
    
    
            let newValue = props.value;
            if (e !== null) {
    
    
                if (/^(?:[1-9][0-9]*)$/.test(e.value)) {
    
    
                    newValue = +e.value;
                } else {
    
    
                    e.value = `${
      
      newValue}`;
                }
            } else {
    
    
                newValue += value;
                if (newValue < 1) {
    
     return; }
            }
            ctx.emit('update:value', newValue);
            ctx.emit('change', newValue);
        };

        return {
    
    
            handleChange,
        };
    },
});
</script>

css

<style lang="scss">
.mall-input-number {
    
    
  display: flex;
  span {
    
    
    cursor: pointer;
  }
  .reduce,
  .increase {
    
    
    display: block;
    width: 29px;
    height: 29px;
    text-align: center;
    line-height: 29px;
    user-select: none;
  }
  .reduce {
    
    
    background: hsla(0, 0%, 96%, 1);
    color: hsla(0, 0%, 33%, 1);
  }
  .text {
    
    
    width: 37px;
    border: 1px solid #f5f5f5;
    font-size: 14px;
    font-weight: 500;
    color: #545454;
    text-align: center;
    line-height: 17px;
  }
  .increase {
    
    
    background: hsla(349, 100%, 45%, 1);
    color: hsla(0, 0%, 100%, 1);
  }
}
</style>

在外面调用 MallInputNumber

   				<MallInputNumber
                      v-model:checked="isLoading"
                      v-model:value="item.quantity"
                      @change="(newValue) => quantityOnChange(item, newValue)"
                    />