flutter中StaggeredGridView上拉刷新触发了，数组也发生了变化，但是列表没有任何变化

Question

flutter中StaggeredGridView上拉刷新触发了，数组也发生了变化，但是列表没有任何变化

class HomeTabPage extends StatefulWidget {
  final String? name;
  final List<BannerMo>? bannerList;
  const HomeTabPage({Key? key,  this.name,  this.bannerList}) : super(key: key);

  @override
  _HomeTabPageState createState() => _HomeTabPageState();
}
const bannerString = "[{\"title\":\"视频1\",\"type\":\"video\",\"url\":\"地址链接\",\"cover\":\"https://img0.baidu.com/it/u=4008146120,512111027&fm=253&app=138&size=w931&n=0&f=JPEG&fmt=auto?sec=1665421200&t=096ce0c96dbc4abbec9fdeb707aa2570\",\"name\":0},"
    "{\"title\":\"网页1\",\"type\":\"url\",\"url\":\"地址链接\",\"cover\":\"https://img1.baidu.com/it/u=3622442929,3246643478&fm=253&app=138&size=w931&n=0&f=JPEG&fmt=auto?sec=1665421200&t=6f3dc0e6a6f0c9d1703612dc581d4bc9\",\"name\":1},"
    "{\"title\":\"视频2\",\"type\":\"video\",\"url\":\"地址链接\",\"cover\":\"https://img1.baidu.com/it/u=3009731526,373851691&fm=253&app=138&size=w931&n=0&f=JPEG&fmt=auto?sec=1665421200&t=63cf502da41c3ccb7f03dd03309fae01\",\"name\":2},"
    "{\"title\":\"网页2\",\"type\":\"url\",\"url\":\"地址链接\",\"cover\":\"https://img2.baidu.com/it/u=1814268193,3619863984&fm=253&app=138&size=w931&n=0&f=JPEG&fmt=auto?sec=1665421200&t=e27eb9d3e19f9d79609023bcd4fc4505\",\"name\":3}]";

class _HomeTabPageState extends State<HomeTabPage> with AutomaticKeepAliveClientMixin{
  List<VideoModel> videoList=[];
  final List bannnerjsonMap=jsonDecode(bannerString);
  ScrollController _scrollController=ScrollController();
  bool _loading=false;
  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    _scrollController.addListener(() {
      var dis=_scrollController.position.maxScrollExtent-_scrollController.position.pixels;
      print('dis:${dis}');
      //当底部距离不足300时加载更多
      if(dis<300){
        if(!_loading){
          _loadDate(loadMore: true);
        }
      }
    });
    _loadDate();
  }
  @override
  Widget build(BuildContext context) {

    return RefreshIndicator(
      onRefresh: _loadDate,
      color: Colors.yellow,
        child: MediaQuery.removePadding(
          removeTop: true,
          context: context,
          child: StaggeredGridView.countBuilder(
            controller: _scrollController,
            crossAxisCount: 2,
            itemCount: videoList.length,
            itemBuilder: (BuildContext context, int index) {
              if (widget.bannerList != null && index == 0) {
                return Padding(
                    padding: EdgeInsets.only(bottom: 8), child: _banner());
              } else {
                return VideoCard(videoModel: videoList[index],);
              }
            },
            staggeredTileBuilder: (int index) {
              if (widget.bannerList != null && index == 0) {
                // Banner 独占两列
                return StaggeredTile.fit(2);
                // return StaggeredTile.count(2,  1);
              } else {
                return StaggeredTile.fit(1);
              }
            },
          ),
        ),
    );
  }

  _banner() {
    return Padding(padding: const EdgeInsets.only(left: 8,right: 8),
    child: HiBanner(bannerList: widget.bannerList!,));
  }

  Future<void> _loadDate({loadMore=false}) async {
    _loading=true;
    print("1111111111");
    for(var a=0;a<3;a++){
      videoList.add(VideoModel.fromJson(bannnerjsonMap[0]));
      videoList.add(VideoModel.fromJson(bannnerjsonMap[1]));
      videoList.add(VideoModel.fromJson(bannnerjsonMap[2]));
      videoList.add(VideoModel.fromJson(bannnerjsonMap[3]));
    }
    print("videolist:${videoList.length}++banner:${widget.bannerList!.length}");
    Future.delayed(Duration(milliseconds: 1000),(){
      _loading=false;
    });

  }
  //列表常驻内存，不会自动刷新
  @override
  // TODO: implement wantKeepAlive
  bool get wantKeepAlive => true;
}

Answer 1

原因是数据更新后没有调用setState(){}方法去刷新页面数据