anchor.diff:      if (selectTime == null && selectType == null) {
         return Container();
       }
  +    var trendTimeList = trendTime(context);
  +    var trendTypeList = trendType(context);
       return new GSYCardItem(
         color: store.state.themeData.primaryColor,
         margin: EdgeInsets.all(0.0),
  
positive.code:   }
  
    ///或者头部可选弹出item容器
    _renderHeaderPopItem(String data, List<TrendTypeModel> list,
        PopupMenuItemSelected<TrendTypeModel> onSelected) {
      return new Expanded(
        child: new PopupMenuButton<TrendTypeModel>(
          child: new Center(
              child: new Text(data, style: GSYConstant.middleTextWhite)),
          onSelected: onSelected,
          itemBuilder: (BuildContext context) {
            return _renderHeaderPopItemChild(list);
  
negative.code: 
    scrollToTop() {
      if (scrollController.offset <= 0) {
        scrollController.animateTo(0, duration: Duration(milliseconds: 600), curve: Curves.linear).then((_) {
          _showRefreshLoading();
        });
      } else {
        scrollController.animateTo(0, duration: Duration(milliseconds: 600), curve: Curves.linear);
      }
    }
  
  