compute() in flutter has no effect - flutter

Question

I try to use compute in Flutter. Here I try to pass multiple parameters inside a Map. But the code in my function myFunction does not work. I get no errors or something else. My code seems to be ignored. Do you find an error here?
Compute function:
Map map = Map();
map['resultList'] = resultList;
map['_getImageFileFromAssets'] = _getImageFileFromAssets;
map["picturesData"] = picturesData;
map["albumID"] = albumID;
await compute(myFunction, map);
Calls the following function:
Future<bool> myFunction(map) async {
var resultList = map["resultList"];
var _getImageFileFromAssets = map["_getImageFileFromAssets"];
var picturesData = map["picturesData"];
var albumID = map["albumID"];
print("Starten");
for (var i = 0; i < resultList.length; i++) {
print(i);
File imageFile = await _getImageFileFromAssets(resultList[i]);
final appDir = await syspath.getApplicationDocumentsDirectory();
final fileName = path.basename(imageFile.path);
final savedImage =
await File(imageFile.path).copy('${appDir.path}/$fileName');
// Creating thumbnails
final thumb = image.decodeImage(await File(savedImage.path).readAsBytes());
final thumbImage = image.copyResize(thumb, width: 500);
new File('${appDir.path}/$fileName-thumb-500.jpg')
.writeAsBytes(image.encodeJpg(thumbImage));
final finalThumbImage = File('${appDir.path}/$fileName-thumb-500.jpg');
picturesData.add(Picture(
album: albumID,
path: savedImage.path,
thumbPath: finalThumbImage.path,
timestamp: Timestamp.now()));
}
return true;
}

Answer 1

Ok, some code - I put this in dartpad.dev:
import 'package:flutter/foundation.dart';
void main() {
Map map = Map();
compute(myFunction, map).then((result) => print(result));
}
Future<bool> myFunction(Map map) async {
print("Starten");
// fake long process
await Future.delayed(Duration(seconds: 5));
return true;
}
and get this as a console result:
Starten
true
Also: is there a reason you need the "map" parameter in your function to be dynamic? If not, I'd declare it as type Map (like I did now).