在构建过程中调用setState()或markNeedsBuild()。(TextInputSettingsTile)

Question

我是新来的，我正在用颤音写我的应用程序的设置部分(我正在使用这个包：屏风)。

我得到了"setState()或markNeedsBuild()在构建过程中调用的错误“。当我的TextInputSettingsTile值发生变化时。

我在网上读了很多信息，但我仍然不明白问题出在哪里。

这是我的main.dart：

import 'package:flutter/material.dart';
import 'pages/home.dart';
import 'pages/settings_page.dart';
import 'package:flutter_settings_screens/flutter_settings_screens.dart';


Future main() async {
  await Settings.init(cacheProvider: SharePreferenceCache());
  
  runApp(const MyApp());
}

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const LoginPage(title: 'TEST'),
    );
  }
}

class LoginPage extends StatefulWidget {
  const LoginPage({Key? key, required this.title}) : super(key: key);
  final String title;

  @override
  State<LoginPage> createState() => LoginPageState();
}

class LoginPageState extends State<LoginPage> {
  final _username = TextEditingController();
  final _password = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('TEST'),
        actions: <Widget>[
          IconButton(
              onPressed: () {
                Navigator.push(
                  context,
                  MaterialPageRoute(builder: (context) => SettingsPage()),
                );
              },
              icon: const Icon(Icons.settings))
        ],
      ),
      body: SingleChildScrollView(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.start,
          children: <Widget>[
            Padding(
              padding: const EdgeInsets.fromLTRB(
                  20, 0, 20, 10),
              child: TextField(
                controller: _username,
                decoration: InputDecoration(
                    icon: const Icon(Icons.email),
                    border: OutlineInputBorder(
                      borderRadius: BorderRadius.circular(15.0),
                    ),
                    labelText: 'username'),
              ),
            ),
            Padding(
                padding: const EdgeInsets.fromLTRB(
                    20, 5, 20, 10),
                child: TextField(
                  controller: _password,
                  obscureText: true,
                  enableSuggestions: false,
                  autocorrect: false,
                  decoration: InputDecoration(
                      icon: const Icon(Icons.password_rounded),
                      border: OutlineInputBorder(
                        borderRadius: BorderRadius.circular(15.0),
                      ),
                      labelText: 'password'),
                )),
            ElevatedButton(
                onPressed: () => {},
                child: const Text('LOGIN'))
          ],
        ),
      ),
    );
  }
}

这是我的设置一般页面：

import 'package:flutter/material.dart';
import 'package:flutter_settings_screens/flutter_settings_screens.dart';
import 'settings/connection_page.dart';


class SettingsPage extends StatefulWidget {
  @override
  SettingsPageState createState() => SettingsPageState();
}

class SettingsPageState extends State<SettingsPage> {
  @override
  Widget build(BuildContext context) => Scaffold(
    appBar: AppBar(
      title: const Text('Settings')
    ),
        body: SafeArea(
          child: ListView(
            padding: const EdgeInsets.all(12),
            children: [
              const SizedBox(height: 5,),
              SettingsGroup(
                  title: 'GENERAL', children: const <Widget>[
                    ConnectionPage()
                  ]
              ),
            ],
          ),
        ),
      );
}

这是我的设置特定页面(在这里我得到了错误)：

import 'package:flutter/material.dart';
import 'package:flutter_settings_screens/flutter_settings_screens.dart';
import 'package:font_awesome_flutter/font_awesome_flutter.dart';

class ConnectionPage extends StatelessWidget {
  const ConnectionPage({Key? key}) : super(key: key);
  static const keyServer = 'key-server';

  @override
  Widget build(BuildContext context) => SimpleSettingsTile(
        title: 'Connection',
        subtitle: 'Parameters',
        leading: const FaIcon(FontAwesomeIcons.clipboardList),
        child: SettingsScreen(
          title: 'Connection',
          children: <Widget>[
            buildServer(),
          ],
        ),
      );

  Widget buildServer() => TextInputSettingsTile(
        settingKey: keyServer,
        title: 'Server',
        initialValue: ''
      );
}

​

我能做些什么来修复这个错误呢？

谢谢你们所有人。

Answer 1

它下面的一些方法是在构建过程中调用setState。标识它并使用addPostFrameCallback方法。示例：

import 'package:flutter/material.dart';
import 'package:flutter_settings_screens/flutter_settings_screens.dart';
import 'settings/connection_page.dart';


class SettingsPage extends StatefulWidget {
  @override
  SettingsPageState createState() => SettingsPageState();
}

class SettingsPageState extends State<SettingsPage> {
  @override
  Widget build(BuildContext context) => Scaffold(
    appBar: AppBar(
      title: const Text('Settings')
    ),
        body: SafeArea(
          child: ListView(
            padding: const EdgeInsets.all(12),
            children: [
              const SizedBox(height: 5,),

             WidgetsBinding.instance.addPostFrameCallback((_){
              SettingsGroup(
                  title: 'GENERAL', children: const <Widget>[
                    ConnectionPage()
                  ]),
             });
            ],
          ),
        ),
      );
}

尝试验证作为此示例。试着把它包装成WidgetsBinding.instance.addPostFrameCallback((_)