anchor.diff:              //TabBar导航标签，底部导航放到Scaffold的bottomNavigationBar中
               controller: _tabController, //配置控制器
               tabs: widget.tabItems,
  -            indicatorColor: widget.indicatorColor, //tab标签的下划线颜色
  +            indicatorColor: _indicatorColor, //tab标签的下划线颜色
             ),
           ));
     }
  
positive.code:   }) : super(key: key);
  
    @override
    _GSYTabBarState createState() => new _GSYTabBarState();
  }
  
  // ignore: mixin_inherits_from_not_object
  class _GSYTabBarState extends State<GSYTabBarWidget> with SingleTickerProviderStateMixin {
  
    _GSYTabBarState();
  
    TabController _tabController;
  
  
negative.code: 
    @override
    Widget build(BuildContext context) {
      if (this._type == GSYTabBarWidget.TOP_TAB) {
        ///顶部tab bar
        return new Scaffold(
          floatingActionButton: _floatingActionButton,
          persistentFooterButtons: _tarWidgetControl == null ? [] : _tarWidgetControl.footerButton,
          appBar: new AppBar(
            backgroundColor: Theme.of(context).primaryColor,
            title: _title,
            bottom: new TabBar(
              controller: _tabController,
              tabs: widget.tabItems,
              indicatorColor: _indicatorColor,
            ),
          ),
          body: new PageView(
            controller: _pageController,
            children: _tabViews,
            onPageChanged: (index) {
              _tabController.animateTo(index);
              _onPageChanged?.call(index);
            },
          ),
        );
  