anchor.diff:    bool get wantKeepAlive => true;
   
     @override
  -  requestRefresh() {
  -
  -  }
  +  requestRefresh() {}
   
     @override
  -  requestLoadMore() {
  -
  -  }
  +  requestLoadMore() {}
   
     @override
     bool get isRefreshFirst => false;
   
  +
     @override
     void initState() {
       super.initState();
  +    WidgetsBinding.instance.addObserver(this);
       ReposDao.getNewsVersion(context, false);
  +  }
   
  +
  +  @override
  +  void dispose() {
  +    WidgetsBinding.instance.removeObserver(this);
  +    super.dispose();
     }
   
     @override
  
positive.code:   _DynamicPageState createState() => _DynamicPageState();
  }
  
  // ignore: mixin_inherits_from_not_object
  class _DynamicPageState extends GSYListState<DynamicPage> {
  
    @override
    Future<Null> handleRefresh() async {
      if (isLoading) {
  
negative.code:       showRefreshLoading();
      }
      super.didChangeDependencies();
    }
  
    @override
    void didChangeAppLifecycleState(AppLifecycleState state) {
      if (state == AppLifecycleState.resumed) {
        if (pullLoadWidgetControl.dataList.length != 0) {
          showRefreshLoading();
        }
      }
    }
  
    _renderEventItem(Event e) {
  