How to get a Uint8List from a Network image by url in Flutter? - flutter

Question

I have the network url of image and I need to get Uint8List. How can I convert it?
I check answers in like question, but those ways don't work.
How to get a Flutter Uint8List from a Network Image?

Answer 1

Try this:
Uint8List bytes = (await NetworkAssetBundle(Uri.parse(url)).load(url))
.buffer
.asUint8List();

Answer 2

Uint8List yourVar;
final DecoderCallback callback = (Uint8List bytes, {int cacheWidth, int cacheHeight}) {
yourVar = bytes.buffer.asUint8List();
return instantiateImageCodec(bytes, targetWidth: cacheWidth, targetHeight: cacheHeight);
};
ImageProvider provider = NetworkImage(yourImageUrl);
provider.obtainKey(createLocalImageConfiguration(context)).then((key) {
provider.load(key, callback);
});

Answer 3

this did the trick for me:
import 'dart:typed_data';
import 'package:flutter/services.dart';
//Get the image from the URL and then convert it to Uint8List
Uint8List bytes = (await NetworkAssetBundle(Uri.parse('https://some_image_url.png'))
.load('https://some_image_url.png'))
.buffer
.asUint8List();

Answer 4

This works on me (using flutter web) with a library file_saver.
Uri uri = Uri.parse(url);
Uint8List bytes = await readBytes(uri);
await FileSaver.instance.saveFile(filename, bytes, 'jpg',
mimeType: MimeType.JPEG); // specify your vars

Answer 5

I'm having the same problem in Flutter web, I had to use the extended_image library, and I found inside your example that has a method that allows you to convert an ImageProvider to Bytes.
https://github.com/fluttercandies/extended_image/blob/master/example/lib/pages/simple/image_editor_demo.dart.
/// it may be failed, due to Cross-domain
Future<Uint8List> _loadNetwork(ExtendedNetworkImageProvider key) async {
try {
final Response response = await HttpClientHelper.get(Uri.parse(key.url),
headers: key.headers,
timeLimit: key.timeLimit,
timeRetry: key.timeRetry,
retries: key.retries,
cancelToken: key.cancelToken);
return response.bodyBytes;
} on OperationCanceledError catch (_) {
print('User cancel request ${key.url}.');
return Future<Uint8List>.error(
StateError('User cancel request ${key.url}.'));
} catch (e) {
return Future<Uint8List>.error(StateError('failed load ${key.url}. \n $e'));
}
}