Dart: The argument type 'Image?' can't be assigned to the parameter type 'Image'

Question

What is the meaning of this error and how to solve it?

Error:

Animation? decodeImage
The argument type 'Image?' can't be assigned to the parameter type 'Image'

Dart Code:

import 'dart:io';
import 'package:image/image.dart';

void main(){

  final image = 'asset/test.webp';

  final bytes = File(image).readAsBytesSync(); // type List<int>
  final decodeImage = decodeWebPAnimation(bytes); // type Animation

  var obj = WebPEncoder(); 

  obj.addFrame(decodeImage?[0]); // gives error

}

What are the methods to fix it?

score 0 · Answer 1 · answered Feb 24 '22 at 17:41

0

Try making it non-null bye adding the bang (!) like so:

  obj.addFrame(decodeImage?[0]!);

answered Feb 24 '22 at 17:41

Josteve

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Thanks for response. tried ( ! ). but it says it will have no effect. – CrackerKSR Feb 24 '22 at 17:51
Okay isolved. I used 'as Image' – CrackerKSR Feb 24 '22 at 18:02
1

Try `decodedImage![0]` instead. (Then worry whether you actually can depend on `decodedImage` not being `null`). – lrn Feb 24 '22 at 19:11

score 0 · Answer 2 · answered Feb 24 '22 at 18:01

0

I fixed it by using as [type]

obj.addFrame(decodeImage?[0] as Image);

Ref: https://stackoverflow.com/a/68969699/9308731

answered Feb 24 '22 at 18:01

CrackerKSR

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Dart: The argument type 'Image?' can't be assigned to the parameter type 'Image'

2 Answers2