Flutter image_picker post upload an image - dart

Question

I am using the Flutter Plugin Image_picker to choose images so that I want to upload image after selected the image
Future<File> _imageFile;
void _onImageButtonPressed(ImageSource source) async {
setState(() {
_imageFile = ImagePicker.pickImage(source: source);
});
}
I find this code in flutter documentation but its not work
var uri = Uri.parse("http://pub.dartlang.org/packages/create");
var request = new http.MultipartRequest("POST", url);
request.fields['user'] = 'nweiz#google.com';
request.files.add(new http.MultipartFile.fromFile(
'package',
new File('build/package.tar.gz'),
contentType: new MediaType('application', 'x-tar'));
request.send().then((response) {
if (response.statusCode == 200) print("Uploaded!");
});

Answer 1

Use MultipartRequest class
Upload(File imageFile) async {
var stream = new http.ByteStream(DelegatingStream.typed(imageFile.openRead()));
var length = await imageFile.length();
var uri = Uri.parse(uploadURL);
var request = new http.MultipartRequest("POST", uri);
var multipartFile = new http.MultipartFile('file', stream, length,
filename: basename(imageFile.path));
//contentType: new MediaType('image', 'png'));
request.files.add(multipartFile);
var response = await request.send();
print(response.statusCode);
response.stream.transform(utf8.decoder).listen((value) {
print(value);
});
}
Check this answer

Answer 2

This code works properly.
Used MultipartRequest class
void uploadImage() async {
File _image;
File pickedImage = await ImagePicker.pickImage(source: ImageSource.camera);
setState(() {
_image = pickedImage;
});
// open a byteStream
var stream = new http.ByteStream(DelegatingStream.typed(_image.openRead()));
// get file length
var length = await _image.length();
// string to uri
var uri = Uri.parse("enter here upload URL");
// create multipart request
var request = new http.MultipartRequest("POST", uri);
// if you need more parameters to parse, add those like this. i added "user_id". here this "user_id" is a key of the API request
request.fields["user_id"] = "text";
// multipart that takes file.. here this "image_file" is a key of the API request
var multipartFile = new http.MultipartFile('image_file', stream, length, filename: basename(_image.path));
// add file to multipart
request.files.add(multipartFile);
// send request to upload image
await request.send().then((response) async {
// listen for response
response.stream.transform(utf8.decoder).listen((value) {
print(value);
});
}).catchError((e) {
print(e);
});
}
name spaces:
import 'package:path/path.dart';
import 'package:async/async.dart';
import 'dart:io';
import 'package:http/http.dart' as http;

Answer 3

If you want the uploading function to return the server response, you can use toBytes() instead of transform(), in order to wait until data transmission is complete.
Future<String> upload() async {
String responseString = '';
// Pick image
final image = await ImagePicker().getImage(
source: ImageSource.gallery // or ImageSource.camera
imageQuality: 100,
maxWidth: 1000,
);
// Convert to File
final file = File(image.path);
// Set URI
final uri = Uri.parse('URL');
// Set the name of file parameter
final parameter = 'Name';
// Upload
final request = http.MultipartRequest('POST', uri)
..files.add(await http.MultipartFile.fromPath(parameter, file.path));
final response = await request.send();
if (response.statusCode == 200) {
responseString = String.fromCharCodes(await response.stream.toBytes());
}
return responseString;
}