Flutter本地文件偏好设置插件local_file_preferences的使用
Flutter本地文件偏好设置插件local_file_preferences的使用
标题
Flutter Local File Preferences
Getting Started 🎉
1pub.dev/packages/local_file_preferences https://mj-studio-library.github.io/flutter-local-file-preferences/
示例代码
import 'package:flutter/material.dart';
import 'package:local_file_preferences/local_file_preferences.dart';
import 'package:shared_preferences/shared_preferences.dart';
void main() async {
var sp = await SharedPreferences.getInstance();
registerGlobalStorage(SharedPreferencesStorage(sharedPreferences: sp));
runApp(const MyApp());
}
class LocalFileCounter with LocalFilePrefMixin<int> {
[@override](/user/override)
int get fallback => 0;
[@override](/user/override)
String get fileName => 'counter.dat';
[@override](/user/override)
int fromJson(Map<String, dynamic> json) {
return json['value'] as int;
}
[@override](/user/override)
Map<String, dynamic> toJson() {
return {'value': value};
}
[@override](/user/override)
Duration get throttleDuration => const Duration(milliseconds: 1);
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
[@override](/user/override)
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
useMaterial3: true,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key, required this.title});
final String title;
[@override](/user/override)
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final _counter = LocalFileCounter();
void _incrementCounter() {
_counter.value += 1;
}
[@override](/user/override)
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Theme.of(context).colorScheme.inversePrimary,
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Text(
'You have pushed the button this many times:',
),
ValueListenableBuilder(
valueListenable: _counter,
builder: (context, value, ) {
return Text(
'$value',
style: Theme.of(context).textTheme.headlineMedium,
);
}),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: const Icon(Icons.add),
),
);
}
}
更多关于Flutter本地文件偏好设置插件local_file_preferences的使用的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html
更多关于Flutter本地文件偏好设置插件local_file_preferences的使用的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html
当然,以下是如何在Flutter项目中使用local_file_preferences
插件来进行本地文件偏好设置的代码案例。请注意,local_file_preferences
并非一个官方或广泛使用的插件名称,但基于你的要求,我将假设这个插件允许你以文件形式存储应用偏好设置。
首先,确保你已经在pubspec.yaml
文件中添加了该插件的依赖(假设插件名称确实为local_file_preferences
,如果实际名称不同,请替换为正确的名称):
dependencies:
flutter:
sdk: flutter
local_file_preferences: ^x.y.z # 替换为实际的版本号
然后,运行flutter pub get
来安装依赖。
接下来,你可以在你的Flutter应用中导入并使用该插件。以下是一个简单的示例,展示如何存储和读取偏好设置:
import 'package:flutter/material.dart';
import 'package:local_file_preferences/local_file_preferences.dart'; // 假设这是插件的导入路径
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Local File Preferences Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
LocalFilePreferences? _preferences;
@override
void initState() {
super.initState();
// 初始化LocalFilePreferences实例
_initializePreferences();
}
Future<void> _initializePreferences() async {
_preferences = LocalFilePreferences.getInstance();
// 读取一个示例设置
String? themeModeKey = await _preferences!.getString('themeMode');
if (themeModeKey != null) {
// 根据读取的设置做一些处理,例如设置应用主题
// 这里只是简单打印出来
print('Read theme mode from preferences: $themeModeKey');
}
}
Future<void> _saveThemeMode(String themeMode) async {
if (_preferences != null) {
await _preferences!.setString('themeMode', themeMode);
print('Saved theme mode to preferences: $themeMode');
}
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Local File Preferences Demo'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
ElevatedButton(
onPressed: () async {
await _saveThemeMode('light');
// 刷新UI或执行其他操作
},
child: Text('Set Theme to Light'),
),
ElevatedButton(
onPressed: () async {
await _saveThemeMode('dark');
// 刷新UI或执行其他操作
},
child: Text('Set Theme to Dark'),
),
],
),
),
);
}
}
请注意,上述代码假设LocalFilePreferences
类提供了getInstance
静态方法用于获取单例实例,以及getString
和setString
方法用于读取和存储字符串类型的偏好设置。实际插件的API可能会有所不同,因此请查阅插件的官方文档以获取准确的API信息。
如果local_file_preferences
插件实际上并不存在,或者你正在寻找一个具体的、广泛使用的插件(如shared_preferences
但用于文件存储),你可能需要寻找或创建一个符合你需求的插件,或者考虑使用其他持久化存储方案,如SQLite数据库或简单的文件I/O操作。