响应式小部件前缀允许您将响应式前缀添加到任何需要缩放或增加字体大小的小部件

          ...
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],

          ...
          children: <Widget>[
            ResponsiveText(
              'You have pushed the button this many times:',
            ),
            ResponsiveText(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],

          ...
          children: <Widget>[
            ResponsiveText(
              'You have pushed the button this many times:',
            ),
            ResponsiveText(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
              scaleMediumTablet: 4,
            ),
          ],

import 'package:responsive_widgets_prefix/responsive_widgets_prefix.dart';

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return ResponsiveMaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return ResponsiveCupertinoApp(
      title: 'Flutter Demo',
      theme: CupertinoThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primaryColor below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primaryColor: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

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

class PlatformApp extends PlatformWidget {

  PlatformApp({
    Key? key,
    required MaterialApp androidApp,
    required CupertinoApp iosApp,
    required TargetPlatform defaultPlatform,
  }) : super(key: key,
      androidBuilder: (BuildContext context) => androidApp,
      iosBuilder:  (BuildContext context) => iosApp
    ) {
      PlatformWidget.setPlatform(defaultPlatform);
  }

}

class PlatformWidget extends StatefulWidget {
  
  static TargetPlatform? _defaultPlatform;

  static get platform {
      if(_defaultPlatform == null) {
        return TargetPlatform.android;
      }
      return _defaultPlatform;
  }

  static get isAndroid {
      return _defaultPlatform == TargetPlatform.android;
  }

  static get isIOS {
      return _defaultPlatform == TargetPlatform.iOS;
  }

  static void setPlatform(TargetPlatform platform) {
      _defaultPlatform = platform;
  }

  static void reassembleApplication() {
      WidgetsBinding.instance!.reassembleApplication();
  }

  const PlatformWidget({
    Key? key,
    required this.androidBuilder,
    required this.iosBuilder,
  }) : super(key: key);

  final WidgetBuilder androidBuilder;
  final WidgetBuilder iosBuilder;

  @override
  State<PlatformWidget> createState() => _PlatformWidgetState();
}

class _PlatformWidgetState extends State<PlatformWidget> {
  @override
  Widget build(context) {
    switch (PlatformWidget._defaultPlatform) {
      case TargetPlatform.android:
        return widget.androidBuilder(context);
      case TargetPlatform.iOS:      
        return widget.iosBuilder(context);        
      default:
        assert(false, 'Unexpected platform ${PlatformWidget._defaultPlatform}');
        return Container();
    }
  }
}

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:responsive_widgets_prefix/responsive_widgets_prefix.dart';

import 'platforms.dart';

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

Widget setupMainWidget() {
  WidgetsFlutterBinding.ensureInitialized();
  return const MyApp();
}
class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override Widget build(BuildContext context) {
    return PlatformApp(
        defaultPlatform: PlatformWidget.platform,
        androidApp: ResponsiveMaterialApp(
          theme: ThemeData(primarySwatch: Colors.blue),
          home: const MyHomePage(title: 'Counter Sample')
        ),
        iosApp: ResponsiveCupertinoApp(
            theme: const CupertinoThemeData(primaryColor: Colors.blue),
            home: const MyHomePage(title: 'Counter Sample'),
        )
    );
  }
}

class MyHomePage extends StatefulWidget {
  final String title;
  const MyHomePage({Key? key, required this.title}) : super(key: key);
  @override State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }
  @override Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text(widget.title)),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            ResponsiveText('You have pushed the button this many times:'),
            ResponsiveText('$_counter', style: Theme.of(context).textTheme.headline4, scaleMediumTablet: 4),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter, tooltip: 'Increment', child: const Icon(Icons.add),
      ),
    );
  }
}