问如何将Xfile转换为文件？

EN

class ImageInput extends StatefulWidget {
  final Function? onSelect;
  const ImageInput({Key? key, this.onSelect}) : super(key: key);

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

class _ImageInputState extends State<ImageInput> {
  File? _imagePicker;

  Future<void> _takeAPicture() async {
    final picker = ImagePicker();
    final imageFile = await picker.pickImage(
      source: ImageSource.gallery,
      maxWidth: 600,
    );
  }
  

  Future<void> _chooseAPicture() async {
    final picker = ImagePicker();
    final imageFile = await picker.pickImage(
      source: ImageSource.camera,
      maxWidth: 600,
    ) as File;
    setState(() {
      _imagePicker = File(imageFile.path);
    });
    final appdir = await syspath.getApplicationDocumentsDirectory();
    final fileName = path.basename(imageFile.path);
    final savedImage = await imageFile.copy('${appdir.path}/${fileName}');
    widget.onSelect!(savedImage);
  }

  @override
  Widget build(BuildContext context) {
    return Row(children: [
      Container(
        child: _imagePicker != null
            ? Image.file(
                _imagePicker as File,
                fit: BoxFit.cover,
                width: double.infinity,
              )
            : Text(
                'No Image Taken',
                textAlign: TextAlign.center,
              ),
        alignment: Alignment.center,
        height: 100,
        width: 100,
        decoration: BoxDecoration(
          border: Border.all(color: Colors.grey, width: 1),
        ),
      ),
      SizedBox(
        height: 10,
      ),
      Expanded(
        child: Column(
          children: [
            TextButton.icon(
              onPressed: () => _takeAPicture(),
              label: Text('choose an Image'),
              style: ButtonStyle(
                textStyle: MaterialStateProperty.all(
                  TextStyle(color: Theme.of(context).primaryColor),
                ),
              ),
              icon: Icon(Icons.camera),
            ),
            TextButton.icon(
              onPressed: () => _chooseAPicture(),
              label: Text('Take an Image'),
              style: ButtonStyle(
                textStyle: MaterialStateProperty.all(
                  TextStyle(color: Theme.of(context).primaryColor),
                ),
              ),
              icon: Icon(Icons.camera_enhance_sharp),
            ),
          ],
        ),
      ),
    ]);
  }
}