Flutter：列表滚动时sliverAppBar调整大小问题

Question

我想在滚动下方的列表时调整sliverAppBar的大小。

现在有两个问题：

1）sliverAppBar在我滚动列表（screenshot）时未调整大小>

2）我找不到用于改变sliverAppBar的子内容大小（screenshot）的示例/解决方案

@override
Widget build(BuildContext context) {
  return Scaffold(
    backgroundColor: Colors.white,
    body: CustomScrollView(
      slivers: <Widget>[
        SliverAppBar( // <-- how to resize on scrolling ListView?
          expandedHeight: 200.0,
          floating: false,
          pinned: true,
          flexibleSpace: SafeArea(
            child: Column(
              children: [
                Row( // <-- how to make it flexible/resizable?
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    Image.asset(
                      'assets/images/user.png',
                      fit: BoxFit.cover,
                      width: 120,
                    )
                  ],
                ),
              ],
            ),
          )
        ),
        SliverFillRemaining(
          child: ListView.builder(
            shrinkWrap: false,
            itemCount: widget.europeanCountries.length,
            itemBuilder: (context, index) {
              return ListTile(
                title: Text(widget.europeanCountries[index]),
              );
            },
          ),
        )
      ],
    ),
    floatingActionButton: FloatingActionButton(
      onPressed: _incrementCounter,
      tooltip: 'Increment',
      child: Icon(Icons.add),
    ), // This trailing comma makes auto-formatting nicer for build methods.
  );
}

我想在滚动下方的列表时调整sliverAppBar的大小。现在有两个问题：1）当我滚动列表时，sliverAppBar不能调整大小（屏幕快照）2）我找不到示例/解决方案...

Answer 1

使用[FlexibleSpaceBar]和[SliverList]