Flutter动态主题切换插件dynamic_theme_nullsafe的使用

Flutter动态主题切换插件dynamic_theme_nullsafe的使用

动态主题切换插件介绍

dynamic_theme_nullsafe 是一个用于在运行时动态切换Flutter应用主题的插件。它允许你轻松地改变应用的主题，并且可以保存这些主题设置。

这个插件可以帮助你在不增加复杂性的前提下，实现动态主题切换功能。

包含在项目中

首先，你需要在你的项目中添加dynamic_theme_nullsafe依赖项：

dependencies:
  dynamic_theme_nullsafe: ^1.0.5

然后运行packages get命令并导入它：

import 'package:dynamic_theme_nullsafe/dynamic_theme_nullsafe.dart';

使用示例

下面是一个完整的示例代码，展示了如何使用dynamic_theme_nullsafe插件来动态切换主题：

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

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

class MyApp extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return DynamicThemeNullsafe(
      defaultThemeMode: ThemeMode.light,
      loadThemeOnStart: true,
      data: (mode) => ThemeData(
        primarySwatch: Colors.indigo,
        brightness: mode == ThemeMode.dark ? Brightness.dark : Brightness.light,
      ),
      themedWidgetBuilder: (
        BuildContext context,
        ThemeMode mode,
        ThemeData? data,
      ) {
        return MaterialApp(
          themeMode: mode,
          title: 'Flutter Demo',
          theme: data,
          home: const MyHomePage(title: 'Flutter Demo Home Page'),
        );
      },
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  [@override](/user/override)
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Easy Theme'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            ElevatedButton(
              onPressed: () {
                DynamicThemeNullsafe.of(context).toggleThemeMode();
              },
              child: const Text('Toggle brightness'),
            ),
            const SizedBox(height: 11),
            ElevatedButton(
              onPressed: changeColor,
              child: const Text('Change color'),
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: showChooser,
        child: const Icon(Icons.add),
      ),
      bottomNavigationBar: BottomNavigationBar(
        items: const <BottomNavigationBarItem>[
          BottomNavigationBarItem(
            icon: Icon(Icons.insert_drive_file),
            label: 'Tab 1',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.show_chart),
            label: 'Tab 2',
          ),
        ],
      ),
    );
  }

  void showChooser() {
    showDialog<void>(
      context: context,
      builder: (BuildContext context) {
        return BrightnessSwitcherDialog(
          onSelectedTheme: (ThemeMode mode) {
            DynamicThemeNullsafe.of(context).setThemeMode(mode);
          },
        );
      },
    );
  }

  void changeColor() {
    DynamicThemeNullsafe.of(context).setThemeData(
      ThemeData(
        primaryColor: Theme.of(context).primaryColor == Colors.indigo
            ? Colors.red
            : Colors.indigo,
      ),
    );
  }
}