casting Box<Map<String , dynamic>> to List<Map<String , dynamic >> throws _CastError

[real-john-doe]

Steps to Reproduce
1 _ Opening box with <Map<>String , dynamic> generic
2 _ adding some valid map to box using put method
3 _ reading box.values from box

Code sample

void main() async {
  await Hive.initFlutter();
  await Hive.openBox<Map<String, dynamic>>('activities');
}

Activity activity = Activity(
    id: 'uniqueId',
    name: 'Doing HomeWork',              
 );

box = Hive.box<Map<String, dynamic>>('activities');
box.put(activity.id, activity.toJson()); // works fine

box = Hive.box<Map<String, dynamic>>('activities');
List<Map<String, dynamic>> list = box.values.toList(); // throws  "type '_InternalLinkedHashMap<dynamic, dynamic>' is not a subtype of type 'Map<String, dynamic>' in type cast" after the first Hot restart or closing and opening application

// stacktarce info doesnt say much , but here it is

When the exception was thrown, this was the stack
#0      Keystore.getValues.<anonymous closure>package:hive/…/box/keystore.dart:122
#1      MappedIterator.moveNext (dart:_internal/iterable.dart:392:20)
#2      new List.from (dart:core-patch/array_patch.dart:50:19)
#3      new List.of (dart:core-patch/array_patch.dart:68:17)
#4      Iterable.toList (dart:core/iterable.dart:404:12)

Version

• Platform: iOS, Android
• Flutter version: 1.22.3 • channel stable
• Hive version: 1.4.4+1
• hive_flutter: 0.3.1

[themisir]

Duplicate of #295

[real-john-doe]

it isnt duplicate of 295 issue,
it doesnt work even after using both of these suggested workarounds

ps: i dont want to use an adapter

Unfortunately this is a limitation of the dart language. You can use

var box = await Hive.openBox<Map>('boxName');
var map = box.get("myMap").cast<String, dynamic>();

or you create an object which contains your box and generate a Hive adapter. The adapter will handle the casting.

Originally posted by @leisim in #295 (comment)

[2shrestha22]

Open box with Map<dynamic, dynamic> and then cast it later.
Do it like this.

void main() async {
  await Hive.initFlutter();
  await Hive.openBox<Map<dynamic, dynamic>>('activities');
}

Activity activity = Activity(
    id: 'uniqueId',
    name: 'Doing HomeWork',              
 );

box = Hive.box<Map<dynamic, dynamic>>('activities');
box.put(activity.id, activity.toJson()); // works fine

box = Hive.box<Map<dynamic, dynamic>>('activities');
List<Map<String, dynamic>> list = box.values.map((e)=> e.cast<String, dynamic>()) .toList();