Flutter determines whether the data is of list type, and then obtains the value inside

  ///处理banner data
  _handlerBannerData(Response response) {
    
    
    if (response.code == 0 || response.code == 200) {
    
    
      List<BannerModel> list = [];
      if (response.data is List) {
    
    //data本来是个对象的，后台返回了个数组，那就判断是否是列表
        (response.data as List).map((e) {
    
    //如果是强转类型，然后循环获取里面的值
          print('广告信息123-$e');
          PrintUtil.prints('banner data=>$e');
          list.add(BannerModel.fromJson(e));//添加在列表里面
        }).toList();
      }
      if (list.isNotEmpty) {
    
    
        _bannersListener.value = list;
        if(list.length>1){
    
    
          widget.controller.stopAutoplay();
          widget.controller.startAutoplay();
        }
      }else {
    
    
        print('广告信息123-为空');
      }
    }
  }