相关疑难解决方法(0)

我已经按照本教程（https://medium.com/@diegoveloper/flutter-collapsing-toolbar-sliver-app-bar-14b858e87abe）创建了一个带有 TabBar 的 CollapsingToolbar。

问题是当我滚动正文的内容时会覆盖 tabBar。

这是代码：

@override
Widget build(BuildContext context) {
return Scaffold(
  body: DefaultTabController(
    length: 2,
    child: NestedScrollView(
      headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
        return <Widget>[
          SliverAppBar(
            expandedHeight: 200.0,
            floating: false,
            pinned: true,
            flexibleSpace: FlexibleSpaceBar(
                centerTitle: true,
                title: Text("Collapsing Toolbar",
                    style: TextStyle(
                      color: Colors.white,
                      fontSize: 16.0,
                    )),
                background: Image.network(
                  "https://images.pexels.com/photos/396547/pexels-photo-396547.jpeg?auto=compress&cs=tinysrgb&h=350",
                  fit: BoxFit.cover,
                )),
          ),
          SliverPersistentHeader(
            delegate: _SliverAppBarDelegate(
              TabBar(
                labelColor: Colors.black87,
                unselectedLabelColor: Colors.grey,
                tabs: [
                  Tab(icon: Icon(Icons.info), text: "Tab 1"),
                  Tab(icon: Icon(Icons.lightbulb_outline), text: "Tab 2"),
                ],
              ), …