使用 JSON 字符串作为中间的介质
void main() async { WidgetsFlutterBinding.ensureInitialized(); await GetStorage.init(); runApp(const MyApp()); } import 'dart:covert'; class Person { final String name; final int age; Person({required this.name, required this.age}); Map<String, dynamic> toMap() { return { "name": name, "age": age, }; } String toJson() => json.encode(toMap()); factory Person.fromMap(Map<String, dynamic> map) { return Person( name: map["name"], age: map["age"], ); } factory Person.fromJson(String value) { return Person.fromMap(json.decode(value)); } } class MyCheckClass { static final personBox = GetStorage(); // personBox.read('person') == null return false after second run this function. and again return TRUE after close the app static checkGetStorage() { Person person = Person(name: "Water", age: 30); if (personBox.read('person') == null) { personBox.write('person', person.toJson()); } } }