import 'package:shared_preferences/shared_preferences.dart'; import 'currency_pair.dart'; const String currencyOne = "conversion_one"; const String currencyTwo = "conversion_two"; class PreferenceProvider { late final SharedPreferences _prefs; Future init() async { _prefs = await SharedPreferences.getInstance(); } Future saveConversionPair(String s1, String s2) async { await _prefs.setString(currencyOne, s1); await _prefs.setString(currencyTwo, s2); } CurrencyPair getConversionPair() { String? s1 = _prefs.getString(currencyOne); String? s2 = _prefs.getString(currencyTwo); return CurrencyPair(s1, s2); } }