Mit dem WeChat-Applet können Sie die Anzahl der Artikel begrenzen, die Sie beim Einkaufen kaufen können (mit Code)

 <view class="num-box">
      <view class="weui-media-box__bd">
          <view class="promotion-sku clear">
             <view class="Spinner">
                <a wx:if="{{goods_count==1}}" class="DisDe">
                     <i bindtap="minusCount" data-index="{{index}}" class="DisDe">-</i>
                </a>
                <a wx:if="{{goods_count>1}}" class="Decrease">
                     <i bindtap="minusCount" data-index="{{index}}" class="DisDe">-</i>
                </a>
             <view>
              <input class="Amount" bindinput="changeCount" type=&#39;number&#39; value="{{goods_count}}" autocomplete="off" maxlength="3"  data-submit_type="{{submit_type}}" />
           </view>
                <a class="Increase">
                   <i bindtap="addCount" data-index="{{index}}" data-submit_type="{{submit_type}}">+</i>
                </a>                   
          </view>
         </view>
      </view>
 </view>

// 增加数量
  addCount(e) {
    // 购买类型，单独购买或拼团购买
    let submit_type = e.target.dataset.submit_type;
    var goods_count = this.data.goods_count;
    goods_count = parseInt(goods_count) + 1;
    //debugger
    if (submit_type == 2) {  // 拼团购买
      var limited_num = this.data.collage.limited_num;
      if (goods_count > limited_num) {
        this.showTip('超出限购');
        return;
      }
    }
    this.setData({
      goods_count: goods_count
    });
  },
// 改变数量(input内的值)
  changeCount(e) {
    var goods_count = e.detail.value;

    let submit_type = e.target.dataset.submit_type;
    if (submit_type == 1) {
      var sys_num = this.data.goods_num;
      if (goods_count > sys_num) {  // 单独购买
        this.showTip('库存不足');
        return;
      }
    } else if (submit_type == 2) {  // 拼团购买
      var limited_num = this.data.collage.limited_num;
      if (goods_count > limited_num) {
        this.showTip('超出限购');
        return;
      }
    }

    if (!(/^[\d]+\.?\d*$/.test(goods_count))) {
      goods_count = goods_count.replace(/\D/g, '');
      return goods_count ? goods_count : 1;
    }
    if (goods_count < 1) {
      return 1;
    }
    this.setData({
      goods_count: goods_count
    });
  },