Flutter:在BottomSheet中移除FAB

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  bool showFab = true;

  void toggleFab() {
    setState(() {
      showFab = !showFab;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Flutter BottomSheet'),
      ),
      body: Center(
        child: RaisedButton(
          child: Text('Show BottomSheet'),
          onPressed: () {
            showModalBottomSheet(
              context: context,
              builder: (BuildContext context) {
                return StatefulBuilder(
                  builder: (BuildContext context, StateSetter setState) {
                    return Container(
                      padding: EdgeInsets.all(16.0),
                      child: Column(
                        mainAxisSize: MainAxisSize.min,
                        children: <Widget>[
                          Text('BottomSheet Content'),
                          if (showFab)
                            FloatingActionButton(
                              child: Icon(Icons.add),
                              onPressed: toggleFab,
                            ),
                        ],
                      ),
                    );
                  },
                );
              },
            );
          },
        ),
      ),
    );
  }
}