Flutter轻量级数据存储插件flutter_lightweight_store的使用

A light weight key-value store (SharedPreferences & NSUserdefaults) with saving to separated/customizable xml/plist.

使用

请运行 <code>example/lib/main.dart</code> 来查看更多演示。

/// 标记此实例为静态，这样可以在整个应用程序中访问它
/// 💚 我们将键值对数据保存到名为 `com.your.name.xml` 的文件中（Android）或 `com.your.name.plist` 的文件中（iOS）
FlutterLightweightStoreModule sp = FlutterLightweightStoreModule("com.your.name");

/// 设置器
await sp.setString("String", "Hello world");
await sp.setInt("Int", 10086);
await sp.setDouble("Double", 10086.12306);
await sp.setBoolean("Boolean", true);

/// 获取器
var str = await sp.getString("String");
var int = await sp.getInt("Int");
var double = await sp.getDouble("Double");
var boolean = await sp.getBoolean("Boolean");

print('✅[SP] 设置器与获取器: 字符串 -> $str, 整数 -> $int, 浮点数 -> $double, 布尔值 -> $boolean');

/// 移除
await sp.removeKey('StringKey');

/// 包含检查
bool isContains = await sp.contains('StringKey');

特性和问题

如果您有任何新功能请求或遇到问题，请在问题追踪器中提出。

以下是完整的示例代码：

import 'dart:convert';

import 'package:path_provider/path_provider.dart';
import 'package:example/flutter_store_instances.dart';
import 'package:flutter/material.dart';
import 'package:flutter_lightweight_store/flutter_lightweight_store.dart';

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

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

  [@override](/user/override)
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  [@override](/user/override)
  void initState() {
    super.initState();

    doStoreTest();

    /// 打印应用程序沙盒目录
    getApplicationDocumentsDirectory().then((value) {
      print('@@@@@@ getApplicationDocumentsDirectory: ${value.absolute.path}');
    });
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: const Text('插件示例应用')),
        body: const Center(child: Text('正在运行于:\n')),
      ),
    );
  }

  void doStoreTest() async {
    {
      FlutterLightweightStoreModule secure = FlutterStoreInstance.secure;
      await secure.setString("String", json.encode({"json": "你🚫好GoodJob"}));
      var str = await secure.getString("String");
      Map map = str != null ? json.decode(str) : null;
      print('@@@@@@ [secure] map: $map');
    }

    {
      FlutterLightweightStoreModule semiSafe = FlutterStoreInstance.semiSafe;
      await semiSafe.setString("String", json.encode({"json": "你🚫好GoodJob"}));
      var str = await semiSafe.getString("String");
      Map map = str != null ? json.decode(str) : null;
      print('@@@@@@ [semiSafe] map: $map');
    }

    {
      FlutterLightweightStoreModule user = FlutterStoreInstance.user;
      await user.setString("String", json.encode({"json": "你🚫好GoodJob"}));
      var str = await user.getString("String");
      Map map = str != null ? json.decode(str) : null;
      print('@@@@@@ [user] map: $map');
    }

    {
      FlutterLightweightStoreModule config = FlutterStoreInstance.config;
      await config.setString("String", json.encode({"json": "你🚫好GoodJob"}));
      var str = await config.getString("String");
      Map map = str != null ? json.decode(str) : null;
      print('@@@@@@ [config] map: $map');
    }

    {
      /// 标记此实例为静态，这样可以在整个应用程序中访问它
      FlutterLightweightStoreModule sp = FlutterLightweightStoreModule("com.your.package.name");
      await sp.setString("StringKey", "Hello world");
      await sp.setInt("IntKey", 10086);
      await sp.setDouble("DoubleKey", 10086.12306);
      await sp.setBoolean("BooleanKey", true);

      var str = await sp.getString("StringKey");
      var int = await sp.getInt("IntKey");
      var double = await sp.getDouble("DoubleKey");
      var boolean = await sp.getBoolean("BooleanKey");
      print('@@@@@@ [SP] 设置器与获取器: 字符串 -> $str, 整数 -> $int, 浮点数 -> $double, 布尔值 -> $boolean');

      await sp.removeKey('StringKey');
      bool isContains = await sp.contains('StringKey');

      FlutterLightweightStoreModule common = FlutterStoreInstance.common;

      /// 包含检查
      String keyContains = '__ok_contains__';
      await common.setBoolean(keyContains, true);
      bool containsVal1 = await common.contains(keyContains);
      await common.removeKey(keyContains);
      bool containsVal2 = await common.contains(keyContains);
      var containsVal3 = await common.getBoolean(keyContains);

      /// 字符串
      String keyString = '__ok_string__';
      await common.setString(keyString, "Hello 💯🐶你好");
      var stringValue1 = await common.getString(keyString);
      await common.setString(keyString, "💯💯💯💯💯💯");
      var stringValue2 = await common.getString(keyString);
      await common.removeKey(keyString);
      var stringValue3 = await common.getString(keyString);

      /// 整数
      String keyInteger = '__ok_int__';
      await common.setInt(keyInteger, 100096666666);
      var intValue1 = await common.getInt(keyInteger);
      await common.setInt(keyInteger, 777777777777);
      var intValue2 = await common.getInt(keyInteger);
      await common.removeKey(keyInteger);
      var intValue3 = await common.getInt(keyInteger);

      /// 浮点数
      String keyDouble = '__ok_double__';
      await common.setDouble(keyDouble, 1009.888);
      var doubleValue1 = await common.getDouble(keyDouble);
      await common.setDouble(keyDouble, 888888.000999);
      var doubleValue2 = await common.getDouble(keyDouble);
      await common.removeKey(keyDouble);
      var doubleValue3 = await common.getDouble(keyDouble);

      /// 布尔值
      String keyBoolean = '__ok_boolean__';
      await common.setBoolean(keyBoolean, true);
      var booleanValue1 = await common.getBoolean(keyBoolean);
      await common.setBoolean(keyBoolean, false);
      var booleanValue2 = await common.getBoolean(keyBoolean);
      await common.removeKey(keyBoolean);
      var booleanValue3 = await common.getBoolean(keyBoolean);

      print('')
          '@@@@@@ [common]'
          '\n'
          '包含检查: $containsVal1, $containsVal2. 如果删除后是否为空? $containsVal3 (${containsVal3 == null}),'
          '\n'
          '字符串: $stringValue1, $stringValue2. 如果删除后是否为空? $stringValue3 (${stringValue3 == null})'
          '\n'
          '整数: $intValue1, $intValue2. 如果删除后是否为空? $intValue3 (${intValue3 == null})'
          '\n'
          '浮点数: $doubleValue1, $doubleValue2. 如果删除后是否为空? $doubleValue3 (${doubleValue3 == null})'
          '\n'
          '布尔值: $booleanValue1, $booleanValue2. 如果删除后是否为空? $booleanValue3 (${booleanValue3 == null})'
          '\n'
          '');

      await common.removeKey("__ok_double__");
      await common.removeKey("__ok_boolean__");
      await common.removeKey("__not_existed_key__");
      print('######################## 基础功能测试完成 ########################');

      String spName = FlutterStoreInstance.common.module;
      Map? result;
      result = await FlutterLightweightStorePlatform.methodChannel.invokeMethod<Map>('setString', []);
      printResult('错误参数', result);

      /// 没有模块或空模块，iOS 中将为 [NSNull null]
      result = await FlutterLightweightStorePlatform.methodChannel
          .invokeMethod<Map>('setString', {'key': 'key', 'value': 'value'});
      printResult('空模块', result);
      result = await FlutterLightweightStorePlatform.methodChannel
          .invokeMethod<Map>('setString', {'module': null, 'key': 'key', 'value': 'value'});
      printResult('空模块', result);

      /// 没有键或空键，iOS 中将为 [NSNull null]
      result = await FlutterLightweightStorePlatform.methodChannel
          .invokeMethod<Map>('setString', {'module': spName, 'value': 'value'});
      printResult('空键', result);
      result = await FlutterLightweightStorePlatform.methodChannel
          .invokeMethod<Map>('setString', {'module': spName, 'key': null, 'value': 'value'});
      printResult('空键', result);

      /// 没有值或空值，iOS 中将为 [NSNull null]
      result = await FlutterLightweightStorePlatform.methodChannel
          .invokeMethod<Map>('setString', {'module': spName, 'key': 'key'});
      printResult('空值', result);
      result = await FlutterLightweightStorePlatform.methodChannel
          .invokeMethod<Map>('setString', {'module': spName, 'key': 'key', 'value': null});
      printResult('空值', result);

      /// 不正确的值
      result = await FlutterLightweightStorePlatform.methodChannel
          .invokeMethod<Map>('setInt', {'module': spName, 'key': 'key', 'value': 0.223});
      printResult('错误的整数值', result);
      result = await FlutterLightweightStorePlatform.methodChannel
          .invokeMethod<Map>('setInt', {'module': spName, 'key': 'key', 'value': '不是整数'});
      printResult('错误的整数类型', result);
      print('######################## 测试结果错误完成 ########################');
    }
  }

  void printResult(String flag, Map? map) {
    print('>>> $flag 结果: ${jsonEncode(map)}');
  }
}

更多关于Flutter轻量级数据存储插件flutter_lightweight_store的使用的实战教程也可以访问 https://www.itying.com/category-92-b0.html

htzhanglong 1楼

更多关于Flutter轻量级数据存储插件flutter_lightweight_store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，下面是一个关于如何使用Flutter轻量级数据存储插件flutter_lightweight_store的示例代码。这个插件通常用于在本地存储键值对数据，非常适合轻量级的数据存储需求。

首先，你需要在你的pubspec.yaml文件中添加这个依赖：

dependencies:
  flutter:
    sdk: flutter
  flutter_lightweight_store: ^x.y.z  # 请替换为最新版本号

然后，运行flutter pub get来安装依赖。

以下是一个完整的示例，演示如何使用flutter_lightweight_store来存储和检索数据：

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

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Lightweight Store Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final LightweightStore store = LightweightStore();
  String? storedValue;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Flutter Lightweight Store Demo'),
      ),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            Text(
              'Stored Value:',
              style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
            ),
            SizedBox(height: 8),
            Text(
              storedValue ?? 'No value stored yet.',
              style: TextStyle(fontSize: 16),
            ),
            SizedBox(height: 24),
            ElevatedButton(
              onPressed: () async {
                // 存储数据
                await store.setItem('myKey', 'Hello, Flutter!');
                
                // 检索数据
                String? value = await store.getItem('myKey');
                
                // 更新状态
                setState(() {
                  storedValue = value;
                });
              },
              child: Text('Store and Retrieve Value'),
            ),
          ],
        ),
      ),
    );
  }
}

在这个示例中，我们做了以下几件事：

引入依赖：在pubspec.yaml文件中添加flutter_lightweight_store依赖。
创建应用：使用MaterialApp创建一个简单的Flutter应用。
状态管理：使用StatefulWidget来管理应用的状态。
存储和检索数据：
- 使用store.setItem('myKey', 'Hello, Flutter!')来存储数据。
- 使用store.getItem('myKey')来检索数据。
- 使用setState来更新UI，显示存储的值。

这个示例展示了如何使用flutter_lightweight_store插件来存储和检索简单的键值对数据。你可以根据需要对这个示例进行扩展和修改，以满足你的具体需求。