原生购物车 Vue 改写

vue购物车
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>购物车</title>
    <link rel="stylesheet" href="static/shoppingcart.css" />
    <script src="https://unpkg.com/vue@next"></script>
  </head>
  <body>
    <div class="box">
      <ul class="list" @change="update">
        <li>
          <span>品名</span><span>数量</span><span>单价</span><span>金额</span>
        </li>
        <itemlist item="手机" price="100"></itemlist>
        <itemlist item="电脑" price="200"></itemlist>
        <itemlist item="相机" price="300"></itemlist>
        <li>
          <span>总计:</span>
          <span class="total-num">{{totalnum}}</span>
          <span class="total-amount">{{totalamount}}</span>
        </li>
      </ul>
      <button class="account">结算</button>
    </div>
    <template id="itemlist">
      <li>
        <span class="content">{{item}}</span>
        <input type="number" min="1" class="num" v-model="num" />
        <span class="price">{{price}}</span>
        <span class="amount">{{payAmount}}</span>
      </li>
    </template>
    <script>
      const app = Vue.createApp({
        data() {
          return {
            totalnum: 0,
            totalamount: 0,
          };
        },
        methods: {
          update() {
            const numarr = [...document.querySelectorAll(".num")].map((item) =>
              parseInt(item.value)
            );
            this.totalnum = numarr.reduce((a, b) => a + b);
            const amountarr = [...document.querySelectorAll(".amount")].map(
              (item) => parseInt(item.innerHTML)
            );
            this.totalamount = amountarr.reduce((a, b) => a + b);
          },
        },
        mounted: function () {
          this.update();
        },
      });
      app.component("itemlist", {
        template: "#itemlist",
        props: ["item", "price"],
        data() {
          return {
            num: 1,
          };
        },
        computed: {
          payAmount() {
            return this.price * this.num;
          },
        },
      });
      app.mount(".box");
    </script>
  </body>
</html>