How to save a list to shared preferences - flutter

Question

I want to save a list to shared preferences, but it doesn't work... The goal is to add data to the variable and save it.
This is the variable I want to save:
var savedData = [
{'date': 0, 'testNumber': 0},
];
And this is the code I tried for saving and receiving the variable:
Future<void> saveDataTest() async {
final prefs = await SharedPreferences.getInstance();
await prefs.setStringList(
'dataTest', savedData.map((i) => i.toString()).toList());
}
Future<String> getDataStringTest() async {
final prefs = await SharedPreferences.getInstance();
savedData =
prefs.getStringList('dataTest').map((i) => int.parse(i)).toList();
setState(() {});
}
This is the error I get:
A value of type 'List<int>' can't be assigned to a variable of type 'List<Map<String, int>>'.
Try changing the type of the variable, or casting the right-hand type to 'List<Map<String, int>>'.

Answer 1

As you are using in your list a Map object with primitive types, you can use jsonEncode and convert to a String that can be saved in sharedPreferences and use jsonDecoder when want to revert.
like this:
String toBeSaved = jsonEncode(savedData);
prefs.setString('dataTest', toBeSaved);

Answer 2

Try using jsonEncode and jsonDecode from import 'dart:convert';
Like so:
Future<void> saveDataTest() async {
final prefs = await SharedPreferences.getInstance();
await prefs.setString("dataTest ", jsonEncode(savedData));
}
Future<String> getDataStringTest() async {
final prefs = await SharedPreferences.getInstance();
savedData = List.from(jsonDecode(prefs.getString("dataTest")));
setState(() {});
}