Flutter 滚动距离来设置TabBar的位置，点击TabBar滚动的到指定的位置

    final tabBarHeight = useRef(42.0);
    final items = useRef(['产品详情', '购买须知', '服务评价']
        .map((e) => Tab(
              height: 40,
              text: e,
            ))
        .toList());
    final tabC = useTabController(initialLength: items.value.length);
    final scroller = useScrollController();

    final isTabClicked = useRef(false);

    final keys = useRef([
      GlobalKey(debugLabel: 'tab1'),
      GlobalKey(debugLabel: 'tab2'),
      GlobalKey(debugLabel: 'tab3'),
    ]);

useEffect(() {
      void tabCL() {
        if (tabC.indexIsChanging) {
          isTabClicked.value = true;
          final keyRenderObject = keys.value[tabC.index].currentContext
              ?.findAncestorRenderObjectOfType();
          scroller.position
              .ensureVisible(keyRenderObject!,
                  duration: const Duration(milliseconds: 300),
                  curve: Curves.easeIn)
              .then((value) {
            isTabClicked.value = false;
          });
        }
      }

      void scrL() {
        if (isTabClicked.value) return;
        int i = 0;
        for (; i < keys.value.length; i++) {
          final keyRenderObject =
              keys.value[i].currentContext?.findAncestorRenderObjectOfType();
          if (keyRenderObject != null) {
            final offsetY =
                (keyRenderObject.parentData as SliverPhysicalParentData)
                    .paintOffset
                    .dy;
            if (offsetY > tabBarHeight.value) {
              break;
            }
          }
        }
        tabC.index = i > 0 ? i - 1 : 0;
      }

      tabC.addListener(tabCL);
      scroller.addListener(scrL);
      return () {
        tabC.removeListener(tabCL);
        scroller.removeListener(scrL);
        tabC.dispose();
        scroller.dispose();
      };
    }, [3]);

CustomScrollView(
        controller: scroller,
        slivers: [
          SliverAppBar(
            backgroundColor: Colors.transparent,
            pinned: true,
            toolbarHeight: 0,
            expandedHeight: 380,
            flexibleSpace: const FlexibleSpaceBar(
              background: HeaderProductDetail(),
            ),
            bottom: PreferredSize(
              preferredSize: Size.fromHeight(tabBarHeight.value),
              child: Container(
                color: Colors.white,
                child: TabBar(
                  tabs: items.value,
                  controller: tabC,
                  unselectedLabelColor: Colors.grey,
                  indicator: context.extensions.underlineTabIndicator,
                ),
              ),
            ),
          ),
          SliverToBoxAdapter(
            child: Container(
              key: keys.value[0],
              height: Screens.height,
              width: double.infinity,
              color: Colors.red,
              child: Text("==============="),
            ),
          ),
          SliverToBoxAdapter(
            child: Container(
              key: keys.value[1],
              height: Screens.height,
              width: double.infinity,
              color: Colors.yellow,
              child: Text("==============="),
            ),
          ),
          SliverToBoxAdapter(
            child: Container(
              key: keys.value[2],
              height: Screens.height,
              width: double.infinity,
              color: Colors.blue,
              child: Text("==============="),
            ),
          )
        ],
      )