Question 323588 in Flutter Question posted in
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Flutter – how resolve that: the constructor being called isnt' a const constructor. Try to remove 'const' from the invocation

import 'package:flutter/material.dart';

class Something {
  Something({required this.first, required this.second});
  final String first;
  final String second;
}

class MapGood extends StatefulWidget {
  const MapGood({Key? key})
      : location = **const** Something(  // the constructor being called isnt' a const constructor. Try to remove 'const' from the invocation.
          first: "37.422",
          second: "-12",
        ),
        super(key: key);

  final Something? location;

  @override
  State<MapGood> createState() => _MapGoodState();
}

class _MapGoodState extends State<MapGood> {
  @override
  Widget build(BuildContext context) {
    return const Placeholder();
  }
}

In const constructor about class Something() in StatefulWidget MapGood is in error, if remove ‘const’ go in error for obvious reason.
Need to create a Stateful like that, where that input can be null, for that reason provide a default values.
I cannot understand how write this condition! i tried all passibility that i know but, every time dart pad (or vsCode) give me some errors.
That solution was give me by Codeium (or AI) and there is this error.

Tags:

2

Answers


  1. 0

    There are too many solutions

    First one :

    class Something {
  Something({required this.first, required this.second});
  final String first;
  final String second;
}

final class MapGood extends StatefulWidget {
   // Remove const 
   MapGood({super.key})
      : location = Something(
          first: '37.422',
          second: '-12',
        );

  final Something? location;

  @override
  State<MapGood> createState() => _MapGoodState();
}

class _MapGoodState extends State<MapGood> {
  @override
  Widget build(BuildContext context) {
    return const Placeholder();
  }
}

    Other :

    class Something {
  const Something({this.first = '37.422', this.second = '-12'});
  final String first;
  final String second;
}

final class MapGood extends StatefulWidget {
  const MapGood({super.key, this.location = const Something()});

  final Something? location;

  @override
  State<MapGood> createState() => _MapGoodState();
}

class _MapGoodState extends State<MapGood> {
  @override
  Widget build(BuildContext context) {
    return const Placeholder();
  }
}
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  2. 0

    Either add const to the Something constructor, like

    const Something({required this.first, required this.second});

    or remove const from both in front of Something and MapGood like

    class MapGood extends StatefulWidget {
  MapGood({Key? key})
      : location =  Something( 
  first: "37.422",
  second: "-12",
  ),
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