SharedPreferences error in Flutter

Question

I was using shared_preferences plugin in my Flutter application. From one moment (probably after Flutter upgrade), it started to throw an exception:

E/flutter (27778): [ERROR:topaz/lib/tonic/logging/dart_error.cc(16)] Unhandled exception:
E/flutter (27778): type '_InternalLinkedHashMap' is not a subtype of type 'Map<String, Object>' where
E/flutter (27778):   _InternalLinkedHashMap is from dart:collection
E/flutter (27778):   Map is from dart:core
E/flutter (27778):   String is from dart:core
E/flutter (27778):   Object is from dart:core
E/flutter (27778): 
E/flutter (27778): #0      SharedPreferences.getInstance (package:shared_preferences/shared_preferences.dart)
E/flutter (27778): <asynchronous suspension>
E/flutter (27778): #1      loadFirstUse (**path**/lib/main.dart:29:53)
E/flutter (27778): <asynchronous suspension>
E/flutter (27778): #2      main (**path**/lib/main.dart:17:9)
E/flutter (27778): <asynchronous suspension>
E/flutter (27778): #3      _startIsolate.<anonymous closure> (dart:isolate/runtime/libisolate_patch.dart:279:19)
E/flutter (27778): #4      _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:165:12)

It happens when I simple try to create instance of SharedPreferences:

SharedPreferences prefs = await SharedPreferences.getInstance();

I was trying to find root of the problem, but was unable to find it. Thank you for any help.

EDIT: I am using shared_preferences: "^0.4.0"

I had this problem using the Dart 2.0 preview. I guess that should be fixed using shared_preferences 0.4.0, which version are you using? — Rene, Mar 21 '18 at 13:15
@NileshRathod Tried to change to "0.2.4" as you suggested, no difference — Tony Danilov, Mar 21 '18 at 13:43
No idea if this will help, but perhaps you could try doing `flutter clean` as well as `pub cache repair` to see if you can shake things out — Ashton Thomas, Mar 21 '18 at 14:25
`pub cache repair` shouldn't be necessary. I need `flutter clean` frequently though to ensure changes take effect. — Günter Zöchbauer, Mar 21 '18 at 14:31
Tried to `pub cache repair` and `flutter clean`, nothing helped — Tony Danilov, Mar 21 '18 at 14:49

score 7 · Answer 1 · edited Jan 18 '22 at 09:15

7

I solved this using the following workaround:

Future<SharedPreferences> prefs = SharedPreferences.getInstance();
prefs.then(
  (pref)
  {
    //call functions like pref.getInt(), etc. here
  }
);

edited Jan 18 '22 at 09:15

Tomerikoo

18,379
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answered Jul 28 '18 at 14:23

Roy

105
1
10

score 6 · Answer 2 · edited Jan 18 '22 at 09:15

To debug this, use the following:

Future<SharedPreferences> _sprefs = SharedPreferences.getInstance();
_sprefs.then((prefs) {
  // ...
}, 
onError: (error) {
  print("SharedPreferences ERROR = $error");   
});

In my case the error was that I wanted to call await SharedPreferences.getInstance() before I called runApp(), so that solution the error message gave me was to order my code as follows:

First:

WidgetsFlutterBinding.ensureInitialized();

Afterwards:

SharedPreferences prefs = await SharedPreferences.getInstance();

Finally:

runApp(...);

score 3 · Accepted Answer · answered Mar 30 '18 at 01:33

3

I've tried shared_preferences: "0.2.4" and other versions suggested above without any success. Finally got it to work after changing flutter channel from dev to beta:

flutter channel beta

At least this fixes this problem for now and just wait for a fix for the shared_preferences plugin on the dev channel.

answered Mar 30 '18 at 01:33

John 0

46
1

I tried this but get the message `git: Already on 'beta'` and I am already using `0.2.4` Still get the same error. – A.W. Jun 13 '18 at 13:00

score 2 · Answer 4 · edited Jan 18 '22 at 09:14

2

I fixed it by changing to shared_preferences: "0.3.3". There is a good chance this breaks again.

edited Jan 18 '22 at 09:14

Tomerikoo

18,379
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answered Apr 25 '18 at 00:08

oreid

1,336
2
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25

I still get the same error after changing to `0.3.3` – A.W. Jun 13 '18 at 13:00
@Guus, yeah, not exactly sure why the fix worked for us. We ended up switching our entire state management to Redux. If you want to continue using shared_preferences, maybe try some other version numbers to see if they fix the issue. Sorry I can't give you a better answer. – oreid Jun 15 '18 at 02:35

score 0 · Answer 5 · answered May 05 '18 at 18:04

0

you need to use Future like this

Future<SharedPreferences> _sprefs = SharedPreferences.getInstance();

answered May 05 '18 at 18:04

parth jansari

138
1
6

Need a more complete example. Can you show code to get a preference, please? – Graham Laight Jun 19 '18 at 15:17

score 0 · Answer 6 · edited Jan 18 '22 at 09:17

0

I remove packages one by one, and found that it was caused by flutter_barcode_scanner. I upgraded it to version 2.0.0 and it solved my problem.

edited Jan 18 '22 at 09:17

Tomerikoo

18,379
16
47
61

answered Jan 18 '22 at 09:09

s k

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SharedPreferences error in Flutter

6 Answers6

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