基于系统暗淡模式的动态主题切换

Question

我一直在研究flutter中的动态暗模式和亮模式功能。

当我从系统设置中更改移动系统的暗/亮模式时，我想将应用程序的主题更改为暗主题或亮主题。

但是，我无法根据移动系统的亮或暗模式来更改应用程序的暗或亮模式。

我使用了下面的代码。

main.dart

    import 'package:flutter/material.dart';
    import 'package:flutterrookieapp/provider/ThemeProvider.dart';
    import 'package:flutterrookieapp/utils/AppTheme.dart';
    import 'package:provider/provider.dart';

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

    class MyApp extends StatelessWidget {
      @override
      Widget build(BuildContext context) {
        return MultiProvider(
          providers: [
            ChangeNotifierProvider(
              create: (context) => ThemeProvider(
                  MediaQuery.of(context).platformBrightness == Brightness.dark
                      ? darkTheme
                      : lightTheme),
            )
          ],
          child: Consumer<ThemeProvider>(
            builder: (temp, theme, _) {
              return MaterialApp(
                debugShowCheckedModeBanner: false,
                title: 'Flutter Sample',
                theme: MediaQuery.platformBrightnessOf(context) == Brightness.dark
                    ? darkTheme
                    : lightTheme,
                home: HomePage(),
              );
            },
          ),
        );
      }
    }
  }

ThemeProvider.dart

import 'package:flutter/material.dart';

class ThemeProvider with ChangeNotifier {
  ThemeData _themeData;

  ThemeProvider(this._themeData);

  ThemeData getTheme() => _themeData;

  setTheme(ThemeData themeData) async {
    this._themeData = themeData;
    notifyListeners();
  }
}

Answer 1

您可以在MaterialApp中使用darkTheme或theme，它始终来自移动系统设置

MaterialApp(
  debugShowCheckedModeBanner: false,
  title: 'Flutter Sample',
  darkTheme: darkTheme,
  theme: lightTheme,
  home: HomePage(),
),