Flutter 中优雅切换应用主题的组件

2024-04-24 19

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简介： 【Flutter】使用adaptive_theme组件优雅切换应用主题：封装MaterialApp，支持light/dark/system模式，自定义色彩，保存选择，含调试按钮。安装配置、设置主题、监听切换、自定义颜色、读取配置步骤详细。代码示例与学习路径推荐。[查看完整教程](https://flutter.ducafecat.com/blog/flutter-app-theme-switch)

Flutter 中优雅切换应用主题的组件

视频

https://youtu.be/L--XLpc452I

https://www.bilibili.com/video/BV1wD421n75p/

前言

原文 https://ducafecat.com/blog/flutter-app-theme-switch

adaptive_theme

Adaptive Theme 这个组件通过包裹 MaterialApp 的方式整体管理 theme 主题，实现如下功能：

切换 light、dark、system 三种模式
自定义色彩
保存主题选择
开启调试按钮

参考

https://pub.dev/packages/adaptive_theme

https://flutter.ducafecat.com/pubs/adaptive_theme-package-info

https://github.com/birjuvachhani/adaptive_theme

步骤

安装配置

https://pub.dev/packages/adaptive_theme

pubspec.yaml

dependencies:
  flutter:
    sdk: flutter

  adaptive_theme: ^3.6.0

lib/main.dart

class MyApp extends StatelessWidget {
   
   
  const MyApp({
   
   super.key});

  @override
  Widget build(BuildContext context) {
   
   
    return AdaptiveTheme(
      light: ThemeData.light(useMaterial3: true),
      dark: ThemeData.dark(useMaterial3: true),
      initial: AdaptiveThemeMode.light,
      debugShowFloatingThemeButton: true,
      builder: (theme, darkTheme) => MaterialApp(
        title: 'Flutter Demo',
        theme: theme,
        darkTheme: darkTheme,
        home: const MyHomePage(title: 'Flutter Demo Home Page'),
      ),
    );
  }
}

debugShowFloatingThemeButton 开启调试按钮

设置主题

设置亮色

ElevatedButton(
  onPressed: () {
   
   
    AdaptiveTheme.of(context).setLight();
  },
  child: const Text('Set Light Theme'),
),

设置暗色

ElevatedButton(
  onPressed: () {
   
   
    AdaptiveTheme.of(context).setDark();
  },
  child: const Text('Set Dark Theme'),
),

设置系统

ElevatedButton(
  onPressed: () {
   
   
    AdaptiveTheme.of(context).setSystem();
  },
  child: const Text('Set System Theme'),
),

toggle 切换

ElevatedButton(
  onPressed: () {
   
   
    AdaptiveTheme.of(context).toggleThemeMode();
  },
  child: const Text('Toggle Theme Mode'),
),

重置样式

ElevatedButton(
  onPressed: () {
   
   
    AdaptiveTheme.of(context).reset();
  },
  child: const Text('Reset Theme'),
),

监听样式切换

// 监听当前样式
ValueListenableBuilder(
  valueListenable: AdaptiveTheme.of(context).modeChangeNotifier,
  builder: (_, mode, child) {
   
   
    return Text(mode.modeName);
  },
),

自定义样式颜色

ElevatedButton(
  onPressed: () {
   
   
    AdaptiveTheme.of(context).setTheme(
      light: ThemeData(
        useMaterial3: true,
        brightness: Brightness.light,
        colorSchemeSeed: Colors.green,
      ),
      dark: ThemeData(
        useMaterial3: true,
        brightness: Brightness.dark,
        colorSchemeSeed: Colors.brown,
      ),
    );
  },
  child: const Text('Change Theme Color'),
),

读取配置

Future<void> main() async {
   
   
  WidgetsFlutterBinding.ensureInitialized();
  final savedThemeMode = await AdaptiveTheme.getThemeMode();
  runApp(MyApp(savedThemeMode: savedThemeMode));
}

class MyApp extends StatelessWidget {
   
   
  final AdaptiveThemeMode? savedThemeMode;

  const MyApp({
   
   super.key, this.savedThemeMode});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
   
   
    return AdaptiveTheme(
      light: ThemeData.light(useMaterial3: true),
      dark: ThemeData.dark(useMaterial3: true),
      initial: savedThemeMode ?? AdaptiveThemeMode.light,
      debugShowFloatingThemeButton: true,
      builder: (theme, darkTheme) => MaterialApp(
        title: 'Flutter Demo',
        theme: theme,
        darkTheme: darkTheme,
        home: const MyHomePage(title: 'Flutter Demo Home Page'),
      ),
    );
  }
}

不要覆盖 key

本地离线采用 shared_preferences 组件，所以不要覆盖键值 adaptive_theme_preferences

https://github.com/BirjuVachhani/adaptive_theme/blob/main/lib/src/adaptive_theme.dart

  /// Key used to store theme information into shared-preferences. If you want
  /// to persist theme mode changes even after shared-preferences
  /// is cleared (e.g. after log out), do not remove this [prefKey] key from
  /// shared-preferences.
  static const String prefKey = 'adaptive_theme_preferences';