Flutter SharedPreference do not persist - dart

Question

I want to save user preferences using Flutter's SharedPreference. But the registered preferences are ALL null at new start (when app have been closed, not unistalled).
settings.dart :
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
class SettingsPage extends StatefulWidget{
#override
_SettingsPageState createState() => new _SettingsPageState();
}
class _SettingsPageState extends State<SettingsPage>{
bool _param1IsON;
bool _param2IsON;
bool _param3IsON;
#override
void initState() {
super.initState();
_param1IsON = false;
_param2IsON = false;
_param3IsON = false;
loadPreferences();
}
Future<Null> loadPreferences() async {
SharedPreferences _preferences = await SharedPreferences.getInstance();
if(_preferences.getBool('setted') == null || !_preferences.getBool('setted'))
SharedPreferences.setMockInitialValues({}); // Library fix line
bool param1IsON = _preferences.getBool('param1IsON');
bool param2IsON = _preferences.getBool('param2IsON');
bool param3IsON = _preferences.getBool('param3IsON');
setState(() {
_param1IsON = (param1IsON != null)? param1IsON : _param1IsON;
_param2IsON = (param2IsON != null)? param2IsON : _param2IsON;
_param3IsON = (param3IsON != null)? param3IsON : _param3IsON;
});
_preferences.setBool('setted', true);
}
Future<Null> setBoolSettings(String key, bool value) async {
switch(key){
case 'param1IsON':
setState(() {
_param1IsON = value;
});
break;
case 'param2IsON':
setState(() {
_param2IsON = value;
});
break;
case 'param3IsON':
setState(() {
_param3IsON = value;
});
break;
default:
print("Unknown settings '$key'");
}
SharedPreferences _preferences = await SharedPreferences.getInstance();
await _preferences.setBool(key, value);
}
#override
Widget build(BuildContext context) {
return new ListView(
children: <Widget>[
new ListTile(
title: new Text(Param 1'),
trailing: new Switch(value: _param1IsON,
onChanged: (bool newValue) {
setBoolSettings('param1IsON', newValue);
}),
),
new ListTile(
title: new Text('Param 2'),
trailing: new Switch(value: _param2IsON,
onChanged: (bool newValue) {
setBoolSettings('param2IsON', newValue);
}),
),
new ListTile(
title: new Text('Param 3'),
trailing: new Switch(value: _param3IsON,
onChanged:
(bool newValue) {
setBoolSettings('param3IsON', newValue);
}),
),
]
);
}
}
What I get:
At lunch 3 parameters are false. If I turn 'ON' one of them, wait 2s (it is not an async problem), then close the app and Start again... All of my parameters are false.
What I want:
At lunch 3 parameters are false. I turn 'ON' one of them. I close the app. Start again. The previous param I turned 'ON' is still true.

Answer 1

I had the same issue and fixed it in Android/../MainActivity.java by adding at the top:
import io.flutter.plugins.GeneratedPluginRegistrant;
As well as under super.onCreate(savedInstanceState);
GeneratedPluginRegistrant.registerWith(this);
The problem comes from using
SharedPreferences.setMockInitialValues({});
I got it from Flutter Test MissingPluginException but it seems to clear all the shared preferences.
However if you remove SharedPreferences.setMockInitialValues({}); and you don't have the two lines above in MainActivity.java, you'll get:
MissingPluginException(No implementation found for method getAll on
channel flutter: plugins.flutter.io/shared_preferences)
I hope it helps!

Answer 2

Hi I also faced the same issue. Did so many things. nothing helped .This may help someone.First thing ,followed this url and did the changes
1.https://github.com/flutter/flutter/wiki/Upgrading-pre-1.12-Android-projects
2.Run the command
flutter upgrade
3.Changed the shared preferences plugin in pubspec.yaml file
shared_preferences: ">=0.5.10 <2.0.0"
4.Deleted the pub cache from installed flutter location
C:\Users\myuser\AppData\Local\Pub\Cache\hosted\pub.dartlang.org
5.flutter build apk --debug
6.flutter build apk --profile
7.flutter run --release (if I run directly this command its throwing error like debug.jar not found , so I ran command 5 and 6 )
Command 7 is for - To Verify whether its working perfectly in release mode.
Finally I tried to generate app build without shrinking the code. then it worked
flutter build apk --no-shrink
flutter build appbundle --no-shrink