Flutter SharedPreferences存储数据基本使用

数据持久化存储
在flutter中使用SharedPreferences 需要异步操作。

添加插件

dependencies:shared_preferences: ^2.5.3

代码

import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';void main() {runApp(MyPage());
}class MyPage extends StatelessWidget {const MyPage({super.key});@overrideWidget build(BuildContext context) {return MaterialApp(theme: ThemeData(), home: MyFul());}
}class MyState extends State {late String str;Future<SharedPreferences> shared = SharedPreferences.getInstance();//获取Flagvoid getValue() async {SharedPreferences sharedPreferences = await shared;bool has = sharedPreferences.containsKey("data");if (has) {str = sharedPreferences.getString("data")!;print(str);}else{print("没有数据");}}//存储flagvoid setValue(String str) async {SharedPreferences sharedPreferences = await shared;sharedPreferences.setString("data", str);print("存储数据");}//删除数据void delValue(String key) async {SharedPreferences sharedPreferences = await shared;sharedPreferences.remove(key);print("删除数据");}@overrideWidget build(BuildContext context) {return Scaffold(appBar: AppBar(title: Text(""), centerTitle: true),body: Column(children: [OutlinedButton(onPressed: () {setValue("hello");},child: Text("存储数据500"),),OutlinedButton(onPressed: () {getValue();},child: Text("获取数据"),),OutlinedButton(onPressed: () {delValue("data");},child: Text("删除数据"),),],),);}
}class MyFul extends StatefulWidget {@overrideState<StatefulWidget> createState() {return MyState();}
}I/flutter (31129): 存储数据
I/flutter (31129): hello
I/flutter (31129): 删除数据
I/flutter (31129): 没有数据