当然，以下是如何在Flutter应用中使用day_night_themed_switcher插件来实现日夜主题切换的代码示例。

首先，确保你已经将day_night_themed_switcher插件添加到你的pubspec.yaml文件中：

dependencies:
  flutter:
    sdk: flutter
  day_night_themed_switcher: ^latest_version  # 请替换为最新的版本号

然后，运行flutter pub get来安装依赖。

1. 初始化主题数据

在你的Flutter项目中，通常会有一个主文件（比如main.dart），在这个文件中初始化主题数据。

import 'package:flutter/material.dart';
import 'package:day_night_themed_switcher/day_night_themed_switcher.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return DayNightThemedSwitcher(
      initialThemeMode: ThemeMode.system, // 可以设置为 system, light, dark
      builder: (context, themeMode) {
        return MaterialApp(
          title: 'Flutter DayNight Theme Switcher',
          theme: ThemeData(
            primarySwatch: Colors.blue,
            brightness: themeMode == ThemeMode.light ? Brightness.light : Brightness.dark,
          ),
          darkTheme: ThemeData(
            primarySwatch: Colors.indigo,
            brightness: Brightness.dark,
          ),
          themeMode: themeMode,
          home: MyHomePage(),
        );
      },
    );
  }
}

2. 创建主页并添加主题切换按钮

接下来，在你的主页（比如MyHomePage.dart）中，添加一个按钮来切换主题。

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:day_night_themed_switcher/day_night_themed_switcher.dart';

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final themeMode = Provider.of<ThemeMode>(context);

    return Scaffold(
      appBar: AppBar(
        title: Text('DayNight Theme Switcher'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'Current Theme Mode: ${themeMode == ThemeMode.light ? 'Light' : themeMode == ThemeMode.dark ? 'Dark' : 'System Default'}',
              style: TextStyle(fontSize: 20),
            ),
            SizedBox(height: 20),
            ElevatedButton(
              onPressed: () {
                DayNightThemedSwitcher.of(context).setThemeMode(
                  themeMode == ThemeMode.light ? ThemeMode.dark : ThemeMode.light,
                );
              },
              child: Text(
                'Switch Theme',
                style: TextStyle(fontSize: 18),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

3. 使用Provider来监听主题变化（可选）

为了确保主题变化能够在整个应用中响应，可以使用Provider来监听主题模式的变化。首先，在你的项目中添加Provider依赖：

dependencies:
  provider: ^latest_version  # 请替换为最新的版本号

然后，在main.dart文件中，用Provider包裹你的MaterialApp：

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:day_night_themed_switcher/day_night_themed_switcher.dart';
import 'MyHomePage.dart';

void main() {
  runApp(
    MultiProvider(
      providers: [
        Provider<ThemeMode>(
          create: (_) => DayNightThemedSwitcher.of(context).themeMode,
        ),
      ],
      child: MyApp(),
    ),
  );
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return DayNightThemedSwitcher(
      initialThemeMode: ThemeMode.system,
      builder: (context, themeMode) {
        return MaterialApp(
          title: 'Flutter DayNight Theme Switcher',
          theme: ThemeData(
            primarySwatch: Colors.blue,
            brightness: themeMode == ThemeMode.light ? Brightness.light : Brightness.dark,
          ),
          darkTheme: ThemeData(
            primarySwatch: Colors.indigo,
            brightness: Brightness.dark,
          ),
          themeMode: themeMode,
          home: MyHomePage(),
        );
      },
    );
  }
}

总结

以上代码展示了如何使用day_night_themed_switcher插件在Flutter中实现日夜主题切换。你可以根据需求进一步定制主题样式和切换逻辑。