CODEWITHSUNDEEP
flutterdartappbarscaffold
Naruto Uzumaki
Naruto Uzumaki

Reputation: 1

Flutter Scaffold(appBar: AppBar()) not working 'const' error

void main() {
  runApp(
    const MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('I am Rich'),
        ),
      ),
    ),
  );
}

this is my code and there is showing "the constructor called is not a constructor"

Error message-

lib/main.dart:8:17: Error: Cannot invoke a non-'const' constructor where a const expression is expected.
Try using a constructor or factory that is 'const'.
        appBar: AppBar(
                ^^^^^^

tried adding 'const' before scaffold

I am sorry for the silly question. I am just a beginner. can't find the solution anywhere else.

Upvotes: 0

Views: 518

Answers (3)

Istinub
Istinub

Reputation: 1

Remove the 'const' before MaterialApp. It should work fine.

the correct code should be

void main() {
  runApp(
    MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('I am Rich'),
        ),
      ),
    ),
  );
}

Upvotes: 0

Mark Toten
Mark Toten

Reputation: 61

To be a bit more precise: AppBar doesn't have a const constructor, so you can't use the const keyword. However, Text does have a const constructor, so you can (should) use const for that one.

void main() {
  runApp(
    MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('I am Rich'),
        ),
      ),
    ),
  );
}

Upvotes: 1

Dilip Kumar
Dilip Kumar

Reputation: 25

Just remove const

void main() {
  runApp(
    MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('I am Rich'),
        ),
      ),
    ),
  );
}

Upvotes: 0

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