Flutter:无法使用TabBar设置SliverPersistentHeader的首选高度

class CustomTabBar extends StatelessWidget implements PreferredSizeWidget {
  @override
  Widget build(BuildContext context) {
    return TabBar(
      tabs: [
        // TabBar的选项卡
      ],
    );
  }

  @override
  Size get preferredSize => Size.fromHeight(kToolbarHeight);
}

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: CustomScrollView(
        slivers: [
          SliverPersistentHeader(
            delegate: MySliverPersistentHeaderDelegate(
              preferredSize: Size.fromHeight(kToolbarHeight),
              child: CustomTabBar(),
            ),
          ),
          // 其他Sliver组件
        ],
      ),
    );
  }
}

class MySliverPersistentHeaderDelegate extends SliverPersistentHeaderDelegate {
  final Size preferredSize;
  final Widget child;

  MySliverPersistentHeaderDelegate({
    required this.preferredSize,
    required this.child,
  });

  @override
  Widget build(BuildContext context, double shrinkOffset, bool overlapsContent) {
    return child;
  }

  @override
  double get maxExtent => preferredSize.height;

  @override
  double get minExtent => preferredSize.height;

  @override
  bool shouldRebuild(covariant MySliverPersistentHeaderDelegate oldDelegate) {
    return child != oldDelegate.child;
  }
}