Dart SliverList没有';添加或删除项目时不更新

Dart SliverList没有';添加或删除项目时不更新,dart,flutter,state,flutter-sliver,Dart,Flutter,State,Flutter Sliver,这是我的代码: class HomeCardList extends StatefulWidget { final Location location; final Position position; HomeCardList(this.location, this.position); @override _HomeCardListState createState() => _HomeCardListState(); } class _HomeCardLis

这是我的代码:

class HomeCardList extends StatefulWidget {
  final Location location;
  final Position position;

  HomeCardList(this.location, this.position);

  @override
  _HomeCardListState createState() => _HomeCardListState();
}

class _HomeCardListState extends State<HomeCardList> {
  List<Widget> _homeCards = [TimeDateCard(), TimeDateCard()];

  @override
  Widget build(BuildContext context) {
    return new CustomScrollView(
      slivers: <Widget>[
        new LocationAppbar(
          location: widget.location,
          position: widget.position,
        ),
        new SliverList(
          delegate: new SliverChildListDelegate(_homeCards),
        ),
        new SliverToBoxAdapter(
          child: RaisedButton(onPressed: () {
            setState(() {
              _homeCards.removeLast();
            });
          }),
        ),
        new SliverFixedExtentList(
            delegate: new SliverChildBuilderDelegate((context, index) {
              return new Text('Item #$index');
            }),
            itemExtent: 320.0)
      ],
    );
  }
}

它会用一个空列表刷新,这里有什么问题吗?

您需要将
\u homeCards
作为一个getter,以便延迟计算,然后
setState
将触发重建尝试调用
setState
中的列表删除项目后,
removeLast()
返回删除的项目。
setState(){
    _homeCards = [];
}