Question 197242 in Flutter Question posted in
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Flutter – LateInitializationError cannot understand why

I am building an app in flutter, and I am trying to open the camera for preview. I keep getting the error LateInitializationError: Field _cameraController I do not see why it’s happening. my code is fairly small and I do not see why it’s complaining.


late List<CameraDescription> cameras;

class AddPostPage extends StatefulWidget {
  const AddPostPage({super.key});

  @override
  _AddPostPageState createState() => _AddPostPageState();
}

class _AddPostPageState extends State<AddPostPage> {
  late CameraController _cameraController;

  @override
  void initState() {
    availableCameras().then((value) {
      cameras = value;
      if (cameras.isEmpty) {}
      _initCameraController(cameras[0]).then((void v) {});
    });
    super.initState();
  }

  Future _initCameraController(CameraDescription cameraDescription) async {
    await _cameraController.dispose();
    _cameraController =
        CameraController(cameraDescription, ResolutionPreset.high);

    _cameraController.addListener(() {
      if (mounted) {
        setState(() {});
      }
    });
    try {
      await _cameraController.initialize();
    } on Exception catch (exception) {
      print(exception);
    }

    if (mounted) {
      setState(() {});
    }
  }

  @override
  Widget build(BuildContext context) {
    return ResponsiveBuilder(
      builder: (BuildContext context, SizingInformation sizingInformation) {
        return Scaffold(
            body: Stack(
          children: [
            Container(
              height: double.infinity,
              child: CameraPreview(_cameraController),
            )
          ],
        ));
      },
    );
  }

  @override
  void dispose() {
    _cameraController.dispose();
    super.dispose();
  }
}

It’s happening at runtime when pressing on the button to access the camera in my app. I am using a iOS simulator

Any idea why ?

Tags:

2

Answers


  1. 0

    may be you try to check if the _cameraController.value.isInitialized before loading camerapreview

    @override   Widget build(BuildContext context) {
    return ResponsiveBuilder(
      builder: (BuildContext context, SizingInformation sizingInformation) {
        return Scaffold(
            body: Stack(
          children: [
            Container(
              height: double.infinity,
              child:  (_cameraController!=null&&_cameraController.value.isInitialized)? 
                     CameraPreview(_cameraController):
                     Center(
                      child: CircularProgressIndicator()
                      ),),
          ],
        ));
      },
    );
}
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  2. 0

    The _cameraController isn’t initialized when you are loading the CameraPreview is the likely culprit. I’d change _cameraController to a nullable instead.

    In build do if _cameraController == null return an indicator or another widget, e.g. Text('Loading ...)`

    Then once the _cameraController is set in SetState it will rebuild, not be null and should load.

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