How to get barcode from PDA scanner device in flutter

Question

My app installs on types of PDA devices (like datalogic, Honeywell, zkc, etc.) I want to get the barcode scanned from these devices. So about this issue, I use RawKeyboardListener like the following code:

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  static const String _title = 'RawKeyboardListener';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: const Text(_title)),
        body: const MyWidget(),
      ),
    );
  }
}

class MyWidget extends StatefulWidget {
  const MyWidget({Key? key}) : super(key: key);

  @override
  State<MyWidget> createState() => MyWidgetState();
}

class MyWidgetState extends State<MyWidget> {
  final FocusNode _focusNode = FocusNode();

  String _chars = '';

  String? barcode;

  @override
  void dispose() {
    _focusNode.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    FocusScope.of(context).requestFocus(_focusNode);
    return Container(
      color: Colors.white,
      alignment: Alignment.center,
      child: RawKeyboardListener(
        focusNode: _focusNode,
        onKey: (RawKeyEvent event) {
          if (event is RawKeyDownEvent || event is RawKeyUpEvent) {
            if (event.physicalKey == PhysicalKeyboardKey.enter) {
              setState(() {
                barcode = _chars;
                _chars = '';
              });
            } else {
              _chars += event.data.keyLabel;
            }
          }
        },
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text(
              'Barcode: $barcode',
            ),
          ],
        ),
      ),
    );
  }
}

This code invokes an onKey callback when scanning the barcode via the PDA scanner, But the barcode (event.data.keyLabel) is empty on datalogic PDA scanner device.

This code works with a handheld scanner as true. I saw this question but it doesn't work for me.

How do I get barcodes from all types of PDA scanners?

Answer 1

It's possible that the data sent by the PDA scanner is not being recognized as key events by the RawKeyboardListener widget. In this case, you may need to use a specialized package for barcode scanning in Flutter.

One popular package for barcode scanning is the flutter_barcode_scanner package. Here's how you can use it in your app:

• Add the flutter_barcode_scanner package to your pubspec.yaml file:

dependencies:
  flutter_barcode_scanner: ^2.0.0

• Import the package in your Dart code:

import 'package:flutter_barcode_scanner/flutter_barcode_scanner.dart';

• Use the FlutterBarcodeScanner.scanBarcode method to scan the barcode:

String barcode = await FlutterBarcodeScanner.scanBarcode(
    '#ff6666', 'Cancel', true, ScanMode.BARCODE);

This method shows a fullscreen scanner that captures the barcode and returns the scanned value as a string. You can then use this value in your app as needed.

Note that this package supports a wide range of barcode formats and can be used with various types of PDA devices.

I hope this helps!

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