how to pass xFile as a function parameter in flutter

Question

I want to upload images to the server using flutter and HTTP package. I am able to display user-selected images but I want to upload them to the server but when I try to pass the image file to the function it gives me an error.

Image Picker Code:

 XFile? uploadimage;
  final ImagePicker _picker = ImagePicker();
  Future<void> chooseImage() async {
    var chooseImage = await _picker.pickImage(source: ImageSource.gallery);
    setState(() {
      uploadimage = chooseImage;
    });
  }

**services file code **

 AdminSupervisorServices.createNewSupervisor(
                                    _nameController.text,
                                    _emailController.text,
                                    _addressController.text,
                                    _siteController.text,
                                    _mobileController.text,
                                    _passwordController.text,
                                    uploadimage // error here
)

function body

 static createNewSupervisor(String name, String email, String address,
      String site, String mobileNumber, String password, File? image) async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    List<int> imageBytes = image!.readAsBytesSync();
    String baseimage = base64Encode(imageBytes);
    var token = prefs.getString("token");
    var response = await http
        .post(Uri.parse("$baseURL/api/mmmmmmmm"), headers: {
      'Authorization': 'Bearer $token',
    }, body: {
      "full_name": name,
      "address": address,
      "mobile_no": mobileNumber,
      "email": email,
      "site_name": site,
      "password": password,
      "image": baseimage,
    });
    print(response.body.toString());
    var data = jsonDecode(response.body);
    return data;
  }
...
}

Answer 1

try this
if this work

    import 'dart:io';
    /////// Import for File

     final File uploadimage = File("");
     final ImagePicker _picker = ImagePicker();
      
    Future<void> chooseImage() async {
        var chooseImage = await _picker.pickImage(source: ImageSource.gallery);
        setState(() {
          uploadimage = File(chooseImage.path);
        });
      }
    
    the function you have
    
    AdminSupervisorServices.createNewSupervisor(
                                    _nameController.text,
                                    _emailController.text,
                                    _addressController.text,
                                    _siteController.text,
                                    _mobileController.text,
                                    _passwordController.text,
                                    uploadimage 
);
    
    static createNewSupervisor(String name, String email, String address,
          String site, String mobileNumber, String password, File? image)async{
    ...
    } 

Edit:

if you are passing image to a json then you missing out is data:image/png;base64 something like this lets assume this function return string.

///include import path
import 'package:path/path.dart' as path;
///////////////////////////////////////


imagetobase64(String? imagePath){
    final extension = path.extension(imagePath
        .substring(imagePath.lastIndexOf("/"))
        .replaceAll("/", ""));
//// the extension return is png or jpg or jpeg which is needed
      final bytes = File(imagePath).readAsBytesSync();
      String base64 =
          "data:image/${extension.replaceAll(".", "")};base64,${base64Encode(bytes)}";

   return base64;

}

Answer 2

uploadimage is of type XFile? and you are passing it to a function which accepts parameter of File? type