flutter-image-upload.dart

///
Future uploadFile(File imageFile, int employeeId) async {
    try {
      EasyLoading.show(status: 'อัปโหลดไฟล์...');
      String token = await storage.read(key: "token");
      await api.uploadImage(employeeId, imageFile, token);
      EasyLoading.showSuccess('อัปโหลดสำเร็จ');
      getEmployees();
    } catch (error) {
      EasyLoading.showError('เกิดข้อผิดพลาด');
      print(error);
    }
  }
///

IconSlideAction(
  caption: 'อัปโหลด',
  color: Colors.teal,
  icon: Icons.camera,
  onTap: () async {
    final pickedFile = await picker.getImage(
        source: ImageSource.gallery,
        imageQuality: 50,
        maxHeight: 680,
        maxWidth: 680);

    if (pickedFile != null) {
      File imageFile = File(pickedFile.path);

      int employeeId =
          int.parse(emp['employee_id'].toString());
      uploadFile(imageFile, employeeId);
    }
  },
),

///
var _rnd = new Random();

setState(() {
  rnd = _rnd.nextInt(10000);
  _token = token;
});

///
CircleAvatar(
  backgroundColor: Colors.grey[100],
  child: Image.network(
    'https://5b32a5b16b98.ngrok.io/libs/image/profile/${emp['employee_id']}?$rnd',
    headers: {"Authorization": "Bearer $_token"},
  ),
)
///

Future<Response> uploadImage(
    int employeeId, File imageFile, String token) async {
  String path = '/employees/$employeeId/upload';

  FormData formData = FormData.fromMap({
    "file": await MultipartFile.fromFile(imageFile.path, filename: basename(imageFile.path))
  });

  return await dio.post(path,
  data: formData,
      options: Options(
          headers: {HttpHeaders.authorizationHeader: 'Bearer $token'}));
}