如何在flutter中更改showModalBottomSheet小部件中CheckboxListTile小部件的值

在showModalSheet内，如果你拨打setState，它不会起作用.您需要在工作表中使用StatefulBuilder.

因此，将modalSheet的内容用StatefulBuilder括起来:

ElevatedButton(
          onPressed: () {
            showModalBottomSheet(
                context: context,
                builder: (BuildContext context) {
                  return StatefulBuilder(
                      builder: (BuildContext context, StateSetter setState) {
                    return SizedBox(
                      height: 500,

下面是一个完整的可运行代码片段:

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Material App',
      home: Scaffold(
        appBar: AppBar(
          title: Text('Material App Bar'),
        ),
        body: Center(child: showModalBottomSheetTester()),
      ),
    );
  }
}

class showModalBottomSheetTester extends StatefulWidget {
  const showModalBottomSheetTester({super.key});

  @override
  State<showModalBottomSheetTester> createState() =>
      _showModalBottomSheetTesterState();
}

class _showModalBottomSheetTesterState
    extends State<showModalBottomSheetTester> {
  bool? _isChecked = false;
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('showModalBottomSheetTester'),
      ),
      body: ElevatedButton(
          onPressed: () {
            showModalBottomSheet(
                context: context,
                builder: (BuildContext context) {
                  return StatefulBuilder(
                      builder: (BuildContext context, StateSetter setState) {
                    return SizedBox(
                      height: 500,
                      child: Column(
                        children: [
                          const Padding(
                            padding: EdgeInsets.only(top: 30.0),
                            child: Text('Head'),
                          ),
                          CheckboxListTile(
                              title: const Text('data'),
                              value: _isChecked,
                              activeColor: Colors.red,
                              checkColor: Colors.blue,
                              tileColor: Colors.green,
                              subtitle: const Text('data'),
                              controlAffinity: ListTileControlAffinity.leading,
                              tristate: true,
                              onChanged: (bool? newValue) {
                                setState(() {
                                  _isChecked = newValue;
                                });
                              })
                        ],
                      ),
                    );
                  });
                });
          },
          child: const Text('press')),
    );
  }
}

See also个

• StatefulBuilder (Widget of the Week) - YouTube video by the official Flutter team.个

• How To Call SetState In Pop-up Alert Dialog - Youtube个