如何允许手势通过堆栈中的小部件？

Question

请看下面的代码示例，或者直接运行here

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) => MaterialApp(
        home: Material(
          child: Stack(
            children: [
              Center(
                child: MaterialButton(
                  color: Colors.white,
                  child: Icon(Icons.ac_unit),
                  onPressed: () => print('pressed'),
                ),
              ),
              CustomScrollWidget()
            ],
          ),
        ),  
      );
}

class CustomScrollWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) => CustomScrollView(
        slivers: <Widget>[
          SliverAppBar(
            pinned: true,
            expandedHeight: MediaQuery.of(context).size.height,
            flexibleSpace: FlexibleSpaceBar(
              title: const Center(child: Text('scroll me')),
            ),
          ),
          const SliverFillRemaining(),
        ],
      );
}

如何允许手势通过堆栈中的小部件？

AFAIK 设置 GestureDetector 的 HitTestBehavior 只会影响孩子， 所以不应该在Stack 中工作，知道吗？

请注意，here 提供的“解决方案”（1、2）不起作用

Answer 1

这不是一个很好的解决方案，但它确实有效：

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) => MaterialApp(
        home: Material(
          child: Stack(
            children: [
              Center(
                child: MaterialButton(
                  color: Colors.white,
                  child: Icon(Icons.ac_unit),
                  onPressed: () {},
                ),
              ),
              CustomScrollWidget(),
              Center(
                child: MaterialButton(
                  elevation: 0.0,
                  hoverColor: Colors.transparent,
                  hoverElevation: 0.0,
                  onPressed: () => print('pressed'),
                ),
              ),
            ],
          ),
        ),  
      );
}

class CustomScrollWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) => CustomScrollView(
        slivers: <Widget>[
          SliverAppBar(
            pinned: true,
            expandedHeight: MediaQuery.of(context).size.height,
            flexibleSpace: FlexibleSpaceBar(
              title: const Center(child: Text('scroll me')),
            ),
          ),
          const SliverFillRemaining(),
        ],
      );
}