vue实现点菜加减

实现点菜加减功能

在Vue中实现点菜加减功能，通常需要以下步骤：

数据模型设计

data() {
  return {
    dishes: [
      { id: 1, name: '鱼香肉丝', price: 28, count: 0 },
      { id: 2, name: '宫保鸡丁', price: 32, count: 0 }
    ]
  }
}

加减方法实现

methods: {
  increaseCount(dish) {
    dish.count++
  },
  decreaseCount(dish) {
    if (dish.count > 0) {
      dish.count--
    }
  }
}

模板部分

<div v-for="dish in dishes" :key="dish.id">
  <span>{{ dish.name }}</span>
  <span>¥{{ dish.price }}</span>
  <button @click="decreaseCount(dish)">-</button>
  <span>{{ dish.count }}</span>
  <button @click="increaseCount(dish)">+</button>
</div>

计算总价功能

添加计算总价的方法：

computed: {
  totalPrice() {
    return this.dishes.reduce((sum, dish) => {
      return sum + dish.price * dish.count
    }, 0)
  }
}

在模板中显示总价：

<div>总价：¥{{ totalPrice }}</div>

样式优化

为加减按钮添加样式：

button {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  border: 1px solid #ccc;
  background: #fff;
  cursor: pointer;
}

button:hover {
  background: #f5f5f5;
}

完整组件示例

<template>
  <div class="menu">
    <div v-for="dish in dishes" :key="dish.id" class="dish-item">
      <span class="name">{{ dish.name }}</span>
      <span class="price">¥{{ dish.price }}</span>
      <button @click="decreaseCount(dish)">-</button>
      <span class="count">{{ dish.count }}</span>
      <button @click="increaseCount(dish)">+</button>
    </div>
    <div class="total">总价：¥{{ totalPrice }}</div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      dishes: [
        { id: 1, name: '鱼香肉丝', price: 28, count: 0 },
        { id: 2, name: '宫保鸡丁', price: 32, count: 0 },
        { id: 3, name: '水煮鱼', price: 45, count: 0 }
      ]
    }
  },
  methods: {
    increaseCount(dish) {
      dish.count++
    },
    decreaseCount(dish) {
      if (dish.count > 0) {
        dish.count--
      }
    }
  },
  computed: {
    totalPrice() {
      return this.dishes.reduce((sum, dish) => {
        return sum + dish.price * dish.count
      }, 0)
    }
  }
}
</script>

<style>
.menu {
  width: 300px;
  margin: 20px auto;
}
.dish-item {
  display: flex;
  align-items: center;
  margin-bottom: 10px;
}
.name {
  flex: 2;
}
.price {
  flex: 1;
  text-align: right;
  margin-right: 15px;
}
.count {
  width: 30px;
  text-align: center;
}
button {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  border: 1px solid #ccc;
  background: #fff;
  cursor: pointer;
}
button:hover {
  background: #f5f5f5;
}
.total {
  margin-top: 20px;
  text-align: right;
  font-weight: bold;
}
</style>

这个实现包含了基本的点菜加减功能，并提供了总价计算和简单样式。可以根据实际需求进一步扩展功能，如添加菜品图片、分类显示等。