I'm working on something currently as a companion to my QR generation plugin (https://github.com/lukef/qr.flutter) but I don't have a specific timeline, unfortunately.

My plan is to use the Texture object and hookup a camera (or fork / use the camera plugin) and then use the Google Vision API (https://developers.google.com/vision/android/barcodes-overview).

It should be decently trivial, I just need to find the time. Either way, that was the plan if you want to do it :)

You can use an open source SDK (e.g., ZXing) or a commercial SDK (e.g., Dynamsoft Barcode Reader SDK) in your Flutter project. Implementing the barcode scanning function is easy.

I have written an article - Flutter Programming with Android AAR File, sharing how to scan QR code in a flutter project. The source code is also available on GitHub.

Java code

private String onGetBarcode(String json) { String filename; try { JSONObject message = new JSONObject(json); filename = message.getString("filename"); } catch (JSONException e) { Log.e(TAG, "JSON exception", e); return null; } String locationProvider; String barcodeResult = "No barcode detected"; File file = new File(filename); if (!file.exists()) { barcodeResult = "No file exists: " + file.toString(); Toast.makeText(BarcodeReaderActivity.this, barcodeResult, Toast.LENGTH_LONG).show(); return null; } else { Bitmap bitmap = BitmapFactory.decodeFile(file.toString()); BarcodeReader reader = new BarcodeReader("license"); ReadResult result = reader.readSingle(bitmap, Barcode.QR_CODE); Barcode[] all = result.barcodes; if (all != null && all.length == 1) { barcodeResult = all[0].displayValue; } else { barcodeResult = "no barcode found: " + file.toString(); } bitmap.recycle(); } JSONObject reply = new JSONObject(); try { if (barcodeResult != null) { reply.put("result", barcodeResult); } else { reply.put("result", "No barcode detected"); } } catch (JSONException e) { Log.e(TAG, "JSON exception", e); return null; } return reply.toString(); } 

Dart code

@override Widget build(BuildContext context) { if (_isExisted) { return new Material( child: new Center( child: new Column( mainAxisAlignment: MainAxisAlignment.spaceEvenly, children: <Widget>[ new Text('Barcode Reader'), new Input( labelText: 'Please input the image path', value: new InputValue(text: _filename), onChanged: onTextChanged, autofocus: true, ), new Row( mainAxisAlignment: MainAxisAlignment.spaceEvenly, children: <Widget>[ new RaisedButton( child: new Text('Read'), onPressed: _getBarcode ), new RaisedButton( child: new Text('Reset'), onPressed: _resetResult ), ] ), new Image.file(new File(_filename)), new Text('$_result'), ] ) ) ); } else { return new Material( child: new Center( child: new Column( mainAxisAlignment: MainAxisAlignment.spaceEvenly, children: <Widget>[ new Text('Barcode Reader'), new Input( labelText: 'Please input the image path', onChanged: onTextChanged, autofocus: true, ), new Row( mainAxisAlignment: MainAxisAlignment.spaceEvenly, children: <Widget>[ new RaisedButton( child: new Text('Read'), onPressed: _getBarcode ), new RaisedButton( child: new Text('Reset'), onPressed: _resetResult ), ] ), new Text('$_result'), ] ) ) ); } } Future<Null> _readBarcode() async { final Map<String, String> message = <String, String>{'filename':_filename}; final Map<String, dynamic> reply = await HostMessages.sendJSON('getBarcode', message); // If the widget was removed from the tree while the message was in flight, // we want to discard the reply rather than calling setState to update our // non-existent appearance. if (!mounted) return; setState(() { _result = reply['result'].toString(); }); } 

Screenshot

So take a little bit of time and do it yourself :)

I used qr_scan. The issue was I created my flutter with objective c. I had to delete iOS and change it.

To do that delete the ios folder from the project and create it with swift.

To create use is command flutter create -i swift . dont forget the . in the end cause it took me a couple of hours to figure that out

According with my researchs there are good options for that:

1. flutter_barcode_scanner (reader)
2. barcode_scan (reader)
3. qr_flutter (thats is for create QR codes)

1st: barcode_scan will works as a wrapper for two commonly used iOS and Android libraries. (iOS: https://github.com/mikebuss/MTBBarcodeScanner, Android: https://github.com/dm77/barcodescanner)

They are in version 3 already and seems like the all the major bugs were resolved.

dependencies: barcode_scan: ^3.0.1 

Here the feature list:

[x] Scan 2D barcodes [x] Scan QR codes [x] Control the flash while scanning [x] Permission handling 

The main warn is about https://github.com/dm77/barcodescanner that's no longer maintained.

The 2nd option is flutter_barcode_scanner thats also works for both android and ios. https://pub.dev/packages/flutter_barcode_scanner For android is just put the pubdev dependency and play, for iOS the only things you need to do is: 1: set minimum deployment target to 11, 2: set Swift version to 5 and 3: ask the permission to use the camera. May the flutter-bardode-scanner is best option since it will depends on just a pubdev dependency without the need of 3rd party project (no longer maintained).

When it's needed to create QR code there is: QR.Flutter also works for ios and android. Features:

[x] Built on QR - Dart [x] Automatic QR code version/type detection or manual entry [x] Supports QR code versions 1 - 40 [x] Error correction / redundancy [x] Configurable output size, padding, background and foreground colors [x] Supports image overlays [x] Export to image data to save to file or use in memory [x] No internet connection required 

Both of them have the best reputation on pub.dev for this propose. So may you need to give a try and check which of them will fill your project needs.

Updating the answer: To read barcode from image gallery there is an alternative package called qr_code_tools. The image could be get from ImagePicker and then decoded to data through QrCodeToolsPlugin.decodeFrom

Getting the image from galley:

ImagePicker.pickImage(source: ImageSource.gallery)); 

Decoding the image to data:

import 'package:qr_code_tools/qr_code_tools.dart'; String _data; Future decode(String file) async { String data = await QrCodeToolsPlugin.decodeFrom(file); setState(() { _data = data; }); }