Flutter：如何将 FloatingActionButton 放在持久底部 sheet 后面？

Question

我想弄清楚是否可以将 FloatingActionButton 放在 BottomSheet 后面，或者换句话说，如何使底部 sheet 位于前面一切显示时。我指的不是模态底部 sheet，而是持久底部。所以我的问题是是否有可能实现或者是否有人可能想分享一些解决方法。

此处您可以看到同时具有持久底部 sheet 和浮动操作按钮时的实际行为示例。

import 'package:flutter/material.dart';

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


class MyApp extends StatelessWidget {
  const MyApp({Key key}) : super(key: key);

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        floatingActionButton: FloatingActionButton(onPressed: (){},),
        appBar: AppBar(title: const Text(_title)),
        body: const MyStatelessWidget(),
      ),
    );
  }
}

class MyStatelessWidget extends StatelessWidget {
  const MyStatelessWidget({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Center(
      child: ElevatedButton(
        child: const Text('showBottomSheet'),
        onPressed: () {
          Scaffold.of(context).showBottomSheet<void>(
                (BuildContext context) {
              return Container(
                height: 200,
                color: Colors.amber,
                child: Center(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    mainAxisSize: MainAxisSize.min,
                    children: <Widget>[
                      const Text('BottomSheet'),
                      ElevatedButton(
                          child: const Text('Close BottomSheet'),
                          onPressed: () {
                            Navigator.pop(context);
                          })
                    ],
                  ),
                ),
              );
            },
          );
        },
      ),
    );
  }
}

提前致谢！

Answer 1

尝试在 body 上使用 Stack 而不是 floatingActionButton，如下所示：

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({Key key}) : super(key: key);

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: const Text(_title)),
        body: Stack(
          children: [
            const MyStatelessWidget(),
            Positioned(
              bottom: 10,
              right: 10,
              child: FloatingActionButton(
                onPressed: () {},
              ),
            )
          ],
        ),
      ),
    );
  }
}

class MyStatelessWidget extends StatelessWidget {
  const MyStatelessWidget({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Center(
      child: ElevatedButton(
        child: const Text('showBottomSheet'),
        onPressed: () {
          Scaffold.of(context).showBottomSheet<void>(
            (BuildContext context) {
              return Container(
                height: 200,
                color: Colors.amber,
                child: Center(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    mainAxisSize: MainAxisSize.min,
                    children: <Widget>[
                      const Text('BottomSheet'),
                      ElevatedButton(
                          child: const Text('Close BottomSheet'),
                          onPressed: () {
                            Navigator.pop(context);
                          })
                    ],
                  ),
                ),
              );
            },
          );
        },
      ),
    );
  }
}

Flutter：如何将 FloatingActionButton 放在持久底部 sheet 后面？

Flutter: How to place a FloatingActionButton behind a persistent bottom sheet?

floating-action-button

flutter