Flutter - How to send multiple images in formdata - flutter

Question

I want to upload multiple images in flutter using dio and formData. What I did is I created a for loop for storing MultipartFile in an array and then I passed the array to the data of "img[]". However, I cannot upload the image if I passed the array but it works perfectly fine if I upload a single image.
Here's my code.
var arr = new List(3);
for (var i=0; i <_tryPath.length; i++) {
arr[i] = await MultipartFile.fromFile(imageFile[i].path, filename:
imageFile[i].path.split('/').last, contentType: new MediaType('image','jpg'));
};
print('this is arr = $arr');
FormData formData = new FormData.fromMap({
"name": "Max",
"location": "Paris",
"age": 21,
"img[]": arr,
});
// dio is in another class here in AuthService.
AuthService().donateRegister(formData).then((val) async {
print('successful');
print(val.data);
});
Can you help me uploading many images in formData? I also would like not to limit the MediaType. What will I do if I will also upload pdf/docu or jpg MediaType? I will appreciate your time and answer. Thank you!

Answer 1

You can use a for loop to set image lists as show below
here I'm using multi_image_picker
Future<int> addMultiImage({MyData myData, List<Asset> files}) async {
var formData = FormData.fromMap({
"name": "Max",
"location": "Paris",
"age": 21,
});
for (int i = 0; i < files.length; i++) {
var path = await FlutterAbsolutePath.getAbsolutePath(files[i].identifier);
formData.files.addAll([
MapEntry("img", await MultipartFile.fromFile(path, filename: path))
]);
}
Response response = await dioHelper.post(
"myPaths",
queryParameters: {
},
data: formData,
);

Answer 2

You can use mime package to get mime type.
import 'package:path/path.dart' as path;
import 'package:mime/mime.dart';
String getFileName(String _path){
return path.basename(_path)
}
FilePickerResult? result = await FilePicker.platform.pickFiles(
allowMultiple: true,
type: FileType.custom,
allowedExtensions: ['jpg', 'pdf', 'doc'],
);
if(result != null) {
List<MultipartFile> files = result.paths.map((path) =>
MultipartFile.fromFileSync(
path,
filename: getFileName(path),
contentType: MediaType(
lookupMimeType(getFileName(path)).split('/')[0],
lookupMimeType(getFileName(path)).split('/')[1],
),
)
).toList();
var dio = Dio();
var formData = FormData.fromMap({
'name': 'wendux', // other parameter may you need to send
'age': 25, // other parameter may you need to send
'files': files,
});
var response = await dio.post('url', data: formData);
// check response status code
if(response.statusCode == 200){
// it's uploaded
}
} else {
// User canceled the picker
}