QR.Flutter Is A Flutter Library for Simple and Fast QR Code

QR.Flutter is a Flutter library for simple and fast QR code rendering via a Widget or custom painter.

Need help?

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Features

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

Installing

Version compatibility: 4.0.0+ supports null safety and requires a version of Flutter that is compatible. If you're using an incompatible version of flutter, please use a 3.x version of this library.

You should add the following to your pubspec.yaml file:

dependencies:
  qr_flutter: ^4.1.0

Note: If you're using the Flutter master channel, if you encounter build issues, or want to try the latest and greatest then you should use the master branch and not a specific release version. To do so, use the following configuration in your pubspec.yaml:

dependencies:
  qr_flutter:
    git:
      url: https://github.com/theyakka/qr.flutter.git

Keep in mind the master branch could be unstable.

After adding the dependency to your pubspec.yaml you can run: flutter packages get or update your packages using your IDE.

Getting started

To start, import the dependency in your code:

import 'package:qr_flutter/qr_flutter.dart';

Next, to render a basic QR code you can use the following code (or something like it):

QrImageView(
  data: '1234567890',
  version: QrVersions.auto,
  size: 200.0,
),

Depending on your data requirements you may want to tweak the QR code output. The following options are available:

Examples

There is a simple, working, example Flutter app in the /example directory. You can use it to play with all the options.

Also, the following examples give you a quick overview on how to use the library.

A basic QR code will look something like:

QrImageView(
  data: 'This is a simple QR code',
  version: QrVersions.auto,
  size: 320,
  gapless: false,
)

A QR code with an image (from your application's assets) will look like:

QrImageView(
  data: 'This QR code has an embedded image as well',
  version: QrVersions.auto,
  size: 320,
  gapless: false,
  embeddedImage: AssetImage('assets/images/my_embedded_image.png'),
  embeddedImageStyle: QrEmbeddedImageStyle(
    size: Size(80, 80),
  ),
)

To show an error state in the event that the QR code can't be validated:

QrImageView(
  data: 'This QR code will show the error state instead',
  version: 1,
  size: 320,
  gapless: false,
  errorStateBuilder: (cxt, err) {
    return Container(
      child: Center(
        child: Text(
          'Uh oh! Something went wrong...',
          textAlign: TextAlign.center,
        ),
      ),
    );
  },
)

Outro

Credits

Thanks to Kevin Moore for his awesome QR - Dart library. It's the core of this library.

For author/contributor information, see the AUTHORS file.

License

QR.Flutter is released under a BSD-3 license. See LICENSE for details.

Use this package as a library

Depend on it

Run this command:

With Flutter:

 $ flutter pub add qr_flutter

This will add a line like this to your package's pubspec.yaml (and run an implicit flutter pub get):

dependencies:
  qr_flutter: ^4.1.0

Alternatively, your editor might support flutter pub get. Check the docs for your editor to learn more.

Import it

Now in your Dart code, you can use:

import 'package:qr_flutter/qr_flutter.dart';

example/lib/main.dart

/*
 * QR.Flutter
 * Copyright (c) 2019 the QR.Flutter authors.
 * See LICENSE for distribution and usage details.
 */

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

import 'main_screen.dart';

void main() => runApp(ExampleApp());

/// The example application class
class ExampleApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    SystemChrome.setSystemUIOverlayStyle(
      const SystemUiOverlayStyle(
        statusBarColor: Colors.white,
        statusBarIconBrightness: Brightness.dark,
        systemNavigationBarColor: Colors.white,
        systemNavigationBarIconBrightness: Brightness.dark,
      ),
    );
    return MaterialApp(
      title: 'QR.Flutter',
      theme: ThemeData.light(),
      debugShowCheckedModeBanner: false,
      home: MainScreen(),
    );
  }
}

Download details:

Author: theyakka.com

Source: https://github.com/theyakka/qr.flutter

#flutter #android #ios #mobile #qr