shared_preferences 是一个简单的，异步的，持久化的 key-value 存储系统

shared_preferences

pub 地址：https://pub.dev/packages/shared_preferences

安装

dependencies:
  shared_preferences: ^2.5.3

写入数据

final prefs = await SharedPreferences.getInstance();

await prefs.setInt('counter', 10);

await prefs.setBool('repeat', true);

await prefs.setDouble('decimal', 1.5);

await prefs.setString('action', 'Start');

await prefs.setStringList('items', <String>['Earth', 'Moon', 'Sun']);

读取数据

// Try reading data from the 'items' key. If it doesn't exist, returns null.
final int? counter = prefs.getInt('counter');

final bool? repeat = prefs.getBool('repeat');

final double? decimal = prefs.getDouble('decimal');

final String? action = prefs.getString('action');

final List<String>? items = prefs.getStringList('items');

删除数据

// Remove data for the 'counter' key.
final success = await prefs.remove('counter');

封装 shared_preferences

import 'dart:convert';
import 'package:shared_preferences/shared_preferences.dart';
class Storage{
  static setData(String key,dynamic value) async{
  SharedPreferences pref=await SharedPreferences.getInstance();
  pref.setString(key, json.encode(value));
  }
  static getData(String key) async{
  SharedPreferences pref=await SharedPreferences.getInstance();
  String? data=pref.getString(key);
  return json.decode(data!);
  }
  static removeData(String key) async{
  SharedPreferences pref=await SharedPreferences.getInstance();
  return pref.remove(key);
  }
}