How to delete picture from the data file in flutter app

Question

In my app I am taking picture and storing it in the device also storing the path using sqlite . Now if I delete the data using the code given below it delete from the local database(sqlite) but do not delete the picture from the file . for example I create 3 transaction and delete 2 of them but in file I still have 3 images(in file) . So how to delete them . please help .

Saving :

Future _takeImage() async {
    PickedFile imageFile = await ImagePicker().getImage(
      source: ImageSource.camera,
      maxWidth: 600,
    );
    _saveImg(imageFile);
  }

  Future _saveImg(PickedFile imageFile) async {
    if (imageFile == null) {
      return;
    }
    setState(() {
      _storedImage = File(imageFile.path);
    });
    final appDirectory = await sysPath.getApplicationDocumentsDirectory();
    final fileName =
        path.basename(_storedImage.path); //name of the photo created by camera.
    final savedImage = await _storedImage
        .copy('${appDirectory.path}/$fileName'); // storing image.
    widget.onSelectImage(savedImage.path);
    
  }

Deleting :

Future<void> deleteExpanse(int id) async {
    try {
      final MyDatabase dbManager = MyDatabase();
      await dbManager.deleteTransaction(id, "Expense");
      DataSample temp = _expenseItems.firstWhere((element) => id == element.id);

      await _deleteImage(temp);

      _expenseItems.removeWhere((element) => element.id == id);
    } catch (error) {
      throw error;
    }
    notifyListeners();
  }

  _deleteImage(DataSample data )async {
      final directory = await getApplicationDocumentsDirectory();
      final path = join(directory.path, data.image );
      bool isExist = await File(path).exists();
      if (isExist) {
        await File(path).delete();

      }

}

for detail code : taking or choosing picture from here and passing it to a method =>

  class ImageInput extends StatefulWidget {
  final Function onSelectImage;
  final String imageFile;

  ImageInput(this.onSelectImage, this.imageFile);

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

class _ImageInputState extends State<ImageInput> {
  File _storedImage;

  Future _choseImage() async {
    try {
      PickedFile imageFile = await ImagePicker().getImage(
        source: ImageSource.gallery,
        maxWidth: 600,
      );
      _saveImg(imageFile);
    } catch (error) {
      throw error;
    }
  }

  Future _takeImage() async {
    try {
      PickedFile imageFile = await ImagePicker().getImage(
        source: ImageSource.camera,
        maxWidth: 600,
      );
      _saveImg(imageFile);
    } catch (error) {
      throw error;
    }
  }

  Future _saveImg(PickedFile imageFile) async {
    try {
      if (imageFile == null) {
        return;
      }
      bool a = await File(imageFile.path).exists();
      setState(() {
        if(a){
          _storedImage = File(imageFile.path);
        }
      });
      final appDirectory = await sysPath.getApplicationDocumentsDirectory();
      final fileName = path
          .basename(_storedImage.path); //name of the photo created by camera.
      final savedImage = await _storedImage
          .copy('${appDirectory.path}/$fileName'); // storing image.
      widget.onSelectImage(savedImage.path);
    } catch (error) {
      throw error;
    }
  }

  @override
  void initState() {
    // TODO: implement initState
    _storedImage = widget.imageFile.isEmpty ? null : File(widget.imageFile);
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Row(
      children: <Widget>[
        Container(
          height: MediaQuery.of(context).size.height * 0.24,
          width: MediaQuery.of(context).size.width * 0.5,
          decoration: BoxDecoration(
            color: Colors.white,
            border: Border.all(width: 1, color: Color(0xFF495464)),
          ),
          child: _storedImage != null
              ? Image.file(
                  _storedImage,
                  fit: BoxFit.cover,
                  width: double.infinity,
                )
              : Text(
                  "No Image Chosen",
                  style: GoogleFonts.courgette(
                      fontSize: MediaQuery.of(context).size.width * 0.05),
                ),
          alignment: Alignment.center,
        ),
        SizedBox(width: 10),
        Expanded(
          child: FittedBox(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                FlatButton.icon(
                  icon: Icon(
                    Icons.camera,
                    color: Color(0xFF495464),
                  ),
                  label: Text(
                    'Take Picture',
                    style: TextStyle(color: Color(0xFF495464), fontSize: 20),
                  ),
                  onPressed: _takeImage,
                ),
                FlatButton.icon(
                  icon: Icon(
                    Icons.photo_library,
                    color: Color(0xFF495464),
                  ),
                  label: Text(
                    'Choose Picture',
                    style: TextStyle(color: Color(0xFF495464), fontSize: 20),
                  ),
                  onPressed: _choseImage,
                ),
              ],
            ),
          ),
        ),
      ],
    );
  }
}

it comes here and then I pass it to the provider delete method given above(I only give the expense delete method above) =>

  var _initState = true;
  var trData;
  String initialPrice = '';

  var _newTransaction = DataSample(
    id: null,
    datetime: null,
    title: '',
    image: '',
    price: 0.0,
    description: '',
  );

  @override
  void didChangeDependencies() {
    if (_initState) {
      trData = ModalRoute.of(context).settings.arguments as Map;
      if (trData['id'] != 0) {
        if (trData['type'] == "Expense") {
          _newTransaction = Provider.of<ExpanseProvider>(context, listen: false)
              .findId(trData['id']);
        } else {
          _newTransaction = Provider.of<IncomeProvider>(context, listen: false)
              .findId(trData['id']);
        }
        _selectedDate = _newTransaction.datetime;
        initialPrice = _newTransaction.price.toString();


      }
    }
    _initState = false;
    super.didChangeDependencies();
  }

  final _gKey = GlobalKey<FormState>();
  DateTime _selectedDate = DateTime.now();

  String _pickedImage = '';

  void _selectImage(String pickedImage) {
    _pickedImage = pickedImage;
  }



  void _saveInput(String page) {
    final _isValid = _gKey.currentState.validate();
    if (!_isValid) {
      return;
    }

    _gKey.currentState.save();
    _newTransaction = DataSample(
      title: _newTransaction.title,
      datetime: _selectedDate,
      image: _pickedImage.isEmpty ? _newTransaction.image : _pickedImage,
      id: _newTransaction.id,
      price: _newTransaction.price,
      description: _newTransaction.description,
    );

    deleteOrUpdate(page);
  }

  Future<void> deleteOrUpdate(String page) async {
    if (_newTransaction.id == null) {
      if (page == 'Expense') {
        await Provider.of<ExpanseProvider>(context, listen: false)
            .addExpanseTransaction(_newTransaction)
            .then((value) => Navigator.of(context).pop())
            .catchError((error) {
          return _onError();
        });
      } else {
        await Provider.of<IncomeProvider>(context, listen: false)
            .addIncomeTransaction(_newTransaction)
            .then((value) => Navigator.of(context).pop())
            .catchError((error) {
          return _onError();
        });
      }
    } else {
      if (page == 'Expense') {
        await Provider.of<ExpanseProvider>(context, listen: false)
            .updateExpense(_newTransaction)
            .then((value) => Navigator.of(context).pop())
            .catchError((error) {
          return _onError();
        });
      } else {
        await Provider.of<IncomeProvider>(context, listen: false)
            .updateIncome(_newTransaction)
            .then((value) => Navigator.of(context).pop())
            .catchError((error) {
          return _onError();
        });
      }
    }
  }
 

Answer 1

I once faced a similar issue using the async file deletion, I then switched to the deleteSync method. I guess in your case it should have no side effect since you already await for deletion. Documentation: https://api.flutter.dev/flutter/dart-io/FileSystemEntity/deleteSync.html