# qr.flutter

**Repository Path**: xiaofan232/qr.flutter

## Basic Information

- **Project Name**: qr.flutter
- **Description**: QR.Flutter is a Flutter library for simple and fast QR code rendering via a Widget or custom painter.
- **Primary Language**: Unknown
- **License**: BSD-3-Clause
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-07-01
- **Last Updated**: 2020-12-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

<img src="https://storage.googleapis.com/product-logos/logo_qr_flutter.png" align="center" width="200">

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

# Features
- Built on [QR - Dart](https://github.com/kevmoo/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

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

```yaml
dependencies:
  qr_flutter: ^3.2.0
```

**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`:
 
```yaml
dependencies:
  qr_flutter:
    git:
      url: git://github.com/lukef/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:

```dart
import 'package:qr_flutter/qr_flutter.dart';
```

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

```dart
QrImage(
  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:

| Property | Type | Description |
|----|----|----|
| `version` | int | `QrVersions.auto` or a value between 1 and 40. See http://www.qrcode.com/en/about/version.html for limitations and details. |
| `errorCorrectionLevel` | int | A value defined on `QrErrorCorrectLevel`. e.g.: `QrErrorCorrectLevel.L`. |
| `size` | double | The (square) size of the image. If not given, will auto size using shortest size constraint. |
| `padding` | EdgeInsets | Padding surrounding the QR code data. |
| `backgroundColor` | Color | The background color (default is none). |
| `foregroundColor` | Color | The foreground color (default is black). |
| `gapless` | bool | Adds an extra pixel in size to prevent gaps (default is true). |
| `errorStateBuilder` | QrErrorBuilder | Allows you to show an error state `Widget` in the event there is an error rendering the QR code (e.g.: version is too low, input is too long, etc). |
| `constrainErrorBounds` | bool | If true, the error `Widget` will be constrained to the square that the QR code was going to be drawn in. If false, the error state `Widget` will grow/shrink to whatever size it needs. |
| `embeddedImage` | ImageProvider | An `ImageProvider` that defines an image to be overlaid in the center of the QR code. |
| `embeddedImageStyle` | QrEmbeddedImageStyle | Properties to style the embedded image. |
| `embeddedImageEmitsError` | bool | If true, any failure to load the embedded image will trigger the `errorStateBuilder` or render an empty `Container`. If false, the QR code will be rendered and the embedded image will be ignored. |

# 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:

```dart
QrImage(
  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:

```dart
QrImage(
  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:

```dart
QrImage(
  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,
        ),
      ),
    );
  },
)
```



# FAQ
## Has it been tested in production? Can I use it in production?

Yep! It's stable and ready to rock. It's currently in use in quite a few production applications including:
- Sixpoint: [Android](https://play.google.com/store/apps/details?id=com.sixpoint.sixpoint&hl=en_US) & [iOS](https://itunes.apple.com/us/app/sixpoint/id663008674?mt=8) 

# Outro
## Credits
Thanks to Kevin Moore for his awesome [QR - Dart](https://github.com/kevmoo/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.