小编Flu*_*008的帖子

按照本教程。https://itnext.io/app-theming-in-flutter-dark-mode-light-mode-27d9adf3cee

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  SystemChrome.setPreferredOrientations([
    DeviceOrientation.portraitUp,
    DeviceOrientation.portraitDown,
  ]);
  runApp(
    ChangeNotifierProvider<AppStateNotifier>(
      builder: (context) => AppStateNotifier(), //<--COMPILER ERROR, details below.
      child: MyApp(),
    ),
  );
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return Consumer<AppStateNotifier>(
      builder: (context, appState, child) {
        return MaterialApp(
          title: 'Lockify',
          debugShowCheckedModeBanner: false,
          theme: AppTheme.lightTheme, 
          darkTheme:
              AppTheme.darkTheme, 
          home: MyHomePage(),
          themeMode: appState.isDarkModeOn ? ThemeMode.dark : ThemeMode.light,
        );
      },
    );
  }
}

错误：编译器消息：lib/main.dart:16:29：错误：“AppStateNotifier”类型的值无法分配给“Widget”类型的变量。

• “AppStateNotifier”来自“package:lockify/appstatenotifier.dart”（“lib/appstatenotifier.dart”）。
• “小部件”来自“package:flutter/src/widgets/framework.dart”（“../../Developer/flutter/packages/flutter/lib/src/widgets/framework.dart”）。构建器：（上下文）=> AppStateNotifier()，

lib/main.dart:16:16: 错误：无法将参数类型“Widget …

import 'package:encrypt/encrypt.dart';
import 'package:encrypt/encrypt_io.dart';
import 'dart:io';
import 'package:pointycastle/asymmetric/api.dart';
import 'dart:async';
import 'package:flutter/services.dart' show rootBundle;

class Encrypt {
  Future<String> loadPrivateKey() async {
    return await rootBundle.loadString('assets/private_key.pem');
  }

  Future<String> loadPublicKey() async {
    return await rootBundle.loadString('assets/public_key.pem');
  }

  encryptString() async {
    print(loadPublicKey().toString());
    final publicKey =
        await parseKeyFromFile<RSAPublicKey>('${loadPublicKey()}');
    final privateKey =
        await parseKeyFromFile<RSAPrivateKey>('${loadPrivateKey()}');

    final plainText = 'James Bond';
    final encrypter =
        Encrypter(RSA(publicKey: publicKey, privateKey: privateKey));

    final encrypted = encrypter.encrypt(plainText);
    final decrypted = encrypter.decrypt(encrypted);

    print(decrypted);
    print(encrypted.base64);
  }
}

错误：正在执行热重载...正在将文件同步到 IA 模拟器上的设备 AOSP...在 1,021 毫秒内重新加载了 707 个库中的 8 …