似乎并没有解决 issue 2 滚动问题

[janjandev]

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

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

class _MyHomePageState extends State<MyHomePage> with SingleTickerProviderStateMixin {
  final List<String> _tabs = [
    "AAA",
    "BBB",
    "CCC",
    "DDD",
    "EEE",
    "FFF",
  ];

  TabController tcl;

  @override
  void initState() {
    super.initState();
    tcl = TabController(length: _tabs.length, vsync: this);
  }

  @override
  void dispose() {
    tcl.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final double statusBarHeight = MediaQuery.of(context).padding.top;
    final double pinnedHeaderHeight = statusBarHeight + kToolbarHeight;

    return extended.NestedScrollView(
      pinnedHeaderSliverHeightBuilder: () {
        return pinnedHeaderHeight;
      },
      innerScrollPositionKeyBuilder: () => Key('${_tabs[tcl.index]}'),
        headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
          // These are the slivers that show up in the "outer" scroll view.
          return <Widget>[
//            SliverOverlapAbsorber(
              // This widget takes the overlapping behavior of the SliverAppBar,
              // and redirects it to the SliverOverlapInjector below. If it is
              // missing, then it is possible for the nested "inner" scroll view
              // below to end up under the SliverAppBar even when the inner
              // scroll view thinks it has not been scrolled.
              // This is not necessary if the "headerSliverBuilder" only builds
              // widgets that do not overlap the next sliver.
//              handle: NestedScrollView.sliverOverlapAbsorberHandleFor(context),
//              sliver:
          SliverAppBar(
                title: const Text('Books'), // This is the title in the app bar.
                pinned: true,
                floating: true,
                snap: true,
                // The "forceElevated" property causes the SliverAppBar to show
                // a shadow. The "innerBoxIsScrolled" parameter is true when the
                // inner scroll view is scrolled beyond its "zero" point, i.e.
                // when it appears to be scrolled below the SliverAppBar.
                // Without this, there are cases where the shadow would appear
                // or not appear inappropriately, because the SliverAppBar is
                // not actually aware of the precise position of the inner
                // scroll views.
                forceElevated: innerBoxIsScrolled,
                bottom: TabBar(
                  controller: tcl,
                  isScrollable: true,
                  // These are the widgets to put in each tab in the tab bar.
                  tabs: _tabs.map((String name) => Tab(text: name)).toList(),
                ),
              ),
//            ),
          ];
        },
        body: TabBarView(
          controller: tcl,
          // These are the contents of the tab views, below the tabs.
          children: _tabs.map((String name) {
            return SafeArea(
              top: false,
              bottom: false,
              child: Builder(
                // This Builder is needed to provide a BuildContext that is
                // "inside" the NestedScrollView, so that
                // sliverOverlapAbsorberHandleFor() can find the
                // NestedScrollView.
                builder: (BuildContext context) {
                  return RefreshIndicator(child: CustomScrollView(
                    // The "controller" and "primary" members should be left
                    // unset, so that the NestedScrollView can control this
                    // inner scroll view.
                    // If the "controller" property is set, then this scroll
                    // view will not be associated with the NestedScrollView.
                    // The PageStorageKey should be unique to this ScrollView;
                    // it allows the list to remember its scroll position when
                    // the tab view is not on the screen.
                    key: PageStorageKey<String>(name),
                    slivers: <Widget>[
//                      SliverOverlapInjector(
//                        // This is the flip side of the SliverOverlapAbsorber
//                        // above.
//                        handle: NestedScrollView.sliverOverlapAbsorberHandleFor(context),
//                      ),
                      SliverPadding(
                        padding: const EdgeInsets.all(0),
                        // In this example, the inner scroll view has
                        // fixed-height list items, hence the use of
                        // SliverFixedExtentList. However, one could use any
                        // sliver widget here, e.g. SliverList or SliverGrid.
                        sliver: TabPage(key: Key(name)),
                      ),
                    ],
                  ), onRefresh: () => Future.delayed(Duration(seconds: 5)));
                },
              ),
            );
          }).toList(),
        ),
      );
  }
}

class TabPage extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return _TabPageState();
  }

  TabPage({Key key}) : super(key: key);
}

class _TabPageState extends State<TabPage> with AutomaticKeepAliveClientMixin {
  @override
  bool get wantKeepAlive => true;

  @override
  Widget build(BuildContext context) {
    super.build(context);
    return extended.NestedScrollViewInnerScrollPositionKeyWidget(
        widget.key,
        SliverFixedExtentList(
          // The items in this example are fixed to 48 pixels
          // high. This matches the Material Design spec for
          // ListTile widgets.
          itemExtent: 48.0,
          delegate: SliverChildBuilderDelegate(
            (BuildContext context, int index) {
              // This builder is called for each child.
              // In this example, we just number each list item.
              return Material(
                  child: ListTile(
                title: Text('Item $index'),
              ));
            },
            // The childCount of the SliverChildBuilderDelegate
            // specifies how many children this inner list
            // has. In this example, each tab has a list of
            // exactly 30 items, but this is arbitrary.
            childCount: 30,
          ),
        ));
  }
}

[zmtzawqlp]

https://github.com/fluttercandies/extended_nested_scroll_view/issues/40 1.17 情况有变化，还在研究

[janjandev]

并且网格列表数据多了滑动很卡顿，代码太侵入官方了。

[zmtzawqlp]

？？对于官方的代码没有太多处理。大部分代码还是跟官方一样的。。你觉得卡顿，需要自己找下原因。我实际项目2层tab，8个列表。没压力

[janjandev]

网格 3 列形式 ，每个列表项是一个卡片里面是图文，加载更多越滑越卡顿

[janjandev]

和列表里面的东西没关系，就是列表数据量大了本身卡顿。

[zmtzawqlp]

图片自己优化下吧，别列表搞一些高清图片