绑定点击事件，判断输入框的值

 <div class="cartWrap">
              <div class="controls">
                <input autocomplete="off" class="itxt" v-model="num" />
                <a class="plus" @click="addNum">+</a>
                <a class="mins" @click="reduceNum">-</a>
              </div>
              <div class="add" @click="addCart">
                <a>加入购物车</a>
              </div>
            </div>

  methods: {
   addNum() {
      this.num++;
    },
    reduceNum() {
      // 1、输入框不能为负数
      if (this.num > 0) {
        this.num--;
      }
    },
    changeNum(num) {
      // 2、输入框不能为非负整数
      console.log("num", num);
      if (isNaN(num) || num < 0) {
        this.num = 1;
      } else {
        this.num = parseInt(num);
      }
    },
    },

添加到购物车

async addCart() {
      try {
        await this.$store.dispatch("addCart", {
          skuId: this.$route.params.skuId,
          skuNum: this.num,
        });
        sessionStorage.setItem("cartList", JSON.stringify(this.skuInfo));
        this.$router.push({ path: "/cart", query: this.num });
      } catch (error) {
        alert("cuo");
      }
    },