Is there a way to scan barcodes in Flutter?

I've previously had a similar problem, and after searching as you did I didn't find a whole lot. I decided that the best approach would be to write a plugin myself... so shameless plug for my plugin here =D, not that I benefit from anyone else using it at all.

You can see it here. However, I haven't had time to document it, test it all that extensively, or publish it properly on Pub. So your mileage may vary. It should however work on android 4.4+ (and maybe below), and iOS devices that flutter supports. I also haven't tested it in conjunction with the Camera plugin but I don't see why it would have a problem with it.

It takes a different approach than most of the other qr code plugins; instead of making an android or iOS window, doing the scan, then returning to flutter, it uses flutter's texture rendering capabilities to have the camera render directly into flutter.

A few more things to consider are that it uses the Google Mobile Vision SDK with the applicable licensing and capabilities that comes along with that (and requires a recent version of Play Services on Android); and that it currently only supports the most basic extraction of information from barcode scans - I only needed the raw text out so that's all I did.

To use it, add this to your pubspec.yaml:

dependencies:  qr_mobile_vision: '^0.0.7'

And implement as follows:

import 'package:qr_mobile_vision/QrCamera.dart';...new Container(  constraints: new BoxConstraints.loose(  new Size(cameraSize, cameraSize)),  child: new QrCamera(    qrCodeCallback: (code) {      print(code);    }  ),)

I do plan on finishing documentation/testing/etc eventually, but you're welcome to try it out in the meantime. If you decide to use it and need a feature it doesn't support I may be able to help implement it... but PRs are welcome and encouraged!

UPDATE: this does include Barcode support now. You can pass in which types of QR code / Barcode you want to support when you instantiate QrCamera. It defaults to all, which takes more processing so if you're after a certain type it's recommended that you pass it in.

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 :)