为什么 sliverlist 在我的 customscrollview 中不起作用？

Question

我正在尝试添加一个 sliverlist，但它对我不起作用，我对使用 flutter 很陌生，我很困惑。

@override
Widget build(BuildContext context) {
return Scaffold(
  body: const CustomScrollView(
    slivers: <Widget>[
      SliverAppBar(
        title: Text('Sample Slivers'),
        leading: Icon(Icons.menu),
        backgroundColor: Colors.orangeAccent,
        expandedHeight: 90.0,
        floating: true,
        pinned: true,
        snap: false,
      ),
      SliverList(
        delegate: SliverChildBuilderDelegate((context) {}),
      )
    ],
  ),
  bottomNavigationBar: _navigatorAppBar(),
  floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
  floatingActionButton: _buildFab(),
);
}
}

Answer 1

1. 删除 CustomScrollView 的 const 关键字。

2. 将SliverChildBuilderDelegate((context) {})替换为：

SliverChildBuilderDelegate((context, index) {})

完整代码：

@override
Widget build(BuildContext context) {
return Scaffold(
  body: CustomScrollView(
    slivers: <Widget>[
      SliverAppBar(
        title: Text('Sample Slivers'),
        leading: Icon(Icons.menu),
        backgroundColor: Colors.orangeAccent,
        expandedHeight: 90.0,
        floating: true,
        pinned: true,
        snap: false,
      ),
      SliverList(
        delegate: SliverChildBuilderDelegate((context, index) {}),
      )
    ],
  ),
  bottomNavigationBar: _navigatorAppBar(),
  floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
  floatingActionButton: _buildFab(),
);
}