anchor.diff:    @override
     Widget build(BuildContext context) {
       super.build(context); // See AutomaticKeepAliveClientMixin.
  -    return GSYPullLoadWidget(
  -      pullLoadWidgetControl,
  -      (BuildContext context, int index) => _renderItem(pullLoadWidgetControl.dataList[index]),
  -      handleRefresh,
  -      onLoadMore,
  -      refreshKey: refreshIndicatorKey,
  +    return new Scaffold(
  +      backgroundColor: Color(GSYColors.mainBackgroundColor),
  +      appBar: new AppBar(
  +        flexibleSpace: _renderHeader(),
  +        backgroundColor: Color(GSYColors.mainBackgroundColor),
  +        leading: new Container(),
  +        elevation: 0.0,
  +      ),
  +      body: GSYPullLoadWidget(
  +        pullLoadWidgetControl,
  +        (BuildContext context, int index) => _renderItem(pullLoadWidgetControl.dataList[index]),
  +        handleRefresh,
  +        onLoadMore,
  +        refreshKey: refreshIndicatorKey,
  +      ),
       );
     }
   }
  +
  +class TrendTypeModel {
  +  final String name;
  +  final String value;
  +
  +  TrendTypeModel(this.name, this.value);
  +}
  
positive.code: import 'package:flutter/material.dart';
  import 'package:gsy_github_app_flutter/common/dao/ReposDao.dart';
  import 'package:gsy_github_app_flutter/common/utils/NavigatorUtils.dart';
  import 'package:gsy_github_app_flutter/widget/GSYListState.dart';
  import 'package:gsy_github_app_flutter/widget/GSYPullLoadWidget.dart';
  import 'package:gsy_github_app_flutter/widget/ReposItem.dart';
  
negative.code: }
  
  class _TrendPageState extends GSYListState<TrendPage> {
    _renderItem(ReposViewModel e) {
      return new ReposItem(e, onPressed: () {
        NavigatorUtils.goReposDetail(context, e.ownerName, e.repositoryName);
      });
    }
  
    _renderHeader() {
      return new GSYCardItem(
        color: Color(GSYColors.primaryValue),
        margin: EdgeInsets.all(10.0),
        shape: new RoundedRectangleBorder(
          borderRadius: BorderRadius.all(Radius.circular(4.0)),
        ),
        child: new Padding(
          padding: new EdgeInsets.only(left: 0.0, top: 5.0, right: 0.0, bottom: 5.0),
          child: new Row(
            children: <Widget>[
              _renderHeaderPopItem("aaa", [new TrendTypeModel("fff", "fff"), new TrendTypeModel("fff", "fff")], (TrendTypeModel result) {
                setState(() {});
              }),
              new Container(height: 10.0, width: 0.5, color: Colors.white),
              _renderHeaderPopItem("bbb", [new TrendTypeModel("fff", "fff"), new TrendTypeModel("fff", "fff")], (TrendTypeModel result) {
                setState(() {});
              }),
            ],
          ),
        ),
      );
    }
  
    _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);
          },
        ),
      );
    }
  
    _renderHeaderPopItemChild(List<TrendTypeModel> data) {
      List<PopupMenuEntry<TrendTypeModel>> list = new List();
      for (TrendTypeModel item in data) {
        list.add(PopupMenuItem<TrendTypeModel>(
          value: item,
          child: new Text(item.name),
        ));
      }
      return list;
    }
  
    @override
  