dynamsoft_capture_vision_flutter 1.1.0

Dynamsoft Capture Vision Flutter SDK provides the ability to decode barcodes, recognize labels, detect and normalize documents.

Dynamsoft Capture Vision Flutter Edition

Dynamsoft Capture Vision (DCV) is an aggregating SDK of a series of specific functional products including:

• Dynamsoft Camera Enhancer (DCE) which provides camera enhancements and UI configuration APIs.
• Dynamsoft Barcode Reader (DBR) which provides barcode decoding algorithm and APIs.
• Dynamsoft Label Recognizer (DLR) which provides label content recognizing algorithm and APIs.
• Dynamsoft Document Normalizer (DDN) which provides document scanning algorithms and APIs.

Note: DCV Flutter edition currently only includes DCE and DBR modules. DLR and DDN modules are still under development and will be included in the future.

Table of Contents

• System Requirements
• Installation
• Build Your Barcode Scanner App
  • Set up Development Environment
  • Initialize the Project
  • Include the Library
  • License Activation
  • Configure the Barcode Reader
  • Build the Widget
  • Run the Project
• Samples
• API References
• License
• Contact

System Requirements

Flutter & Dart

• Flutter version: >=2.0.0
• Dart version: >=2.12.0 <3.0.0

Android

• Supported OS: Android 5.0 (API Level 21) or higher.
• Supported ABI: armeabi-v7a, arm64-v8a, x86 and x86_64.
• Development Environment: Android Studio 3.4+ (Android Studio 4.2+ recommended).
• JDK: 1.8+

iOS

• Supported OS: iOS 10.0 or higher.
• Supported ABI: arm64 and x86_64.
• Development Environment: Xcode 7.1 and above (Xcode 13.0+ recommended), CocoaPods 1.11.0+.

Installation

Run the following command:

flutter pub add dynamsoft_capture_vision_flutter

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

dependencies:
   dynamsoft_capture_vision_flutter: ^1.1.0

Build Your Barcode Scanner App

Now you will learn how to create a simple barcode scanner using Dynamsoft Capture Vision Flutter SDK.

Note: You can get the full source code of a similar project: Barcode Reader Simple Sample

Set up Development Environment

If you are a beginner with Flutter, please follow the guide on the Flutter official website to set up the development environment.

Initialize the Project

Create a new Flutter project.

flutter create simple_barcode_scanner

Include the Library

View the installation section on how to add the library. In main.dart of your project, import the library.

import 'package:dynamsoft_capture_vision_flutter/dynamsoft_capture_vision_flutter.dart';

License Activation

The barcode reading module of Dynamsoft Capture Vision needs a valid license to work. Please refer to the Licensing section for more info on how to obtain a license. In the main() function, add the following code to activate the license:

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  // Put your Dynamsoft Barcode Reader license here.
  const String licenseKey = '';
  // Initialize the license so that you can use full feature of the Barcode Reader module.
  try {
    await DCVBarcodeReader.initLicense(license: licenseKey);
  } catch (e) {
    print(e);
  }

  runApp(const MyApp());
}

Configure the Barcode Reader

In this section, we are going to work on the _MyHomePageState class in the newly created project to add the barcode decoding feature.

Add the following instance variables:

class _MyHomePageState extends State<MyHomePage> {
  late final DCVBarcodeReader _barcodeReader;
  late final DCVCameraEnhancer _cameraEnhancer;
  final DCVCameraView _cameraView = DCVCameraView();
  List<BarcodeResult> decodeResults = [];
}

• _barcodeReader: The object that implements the barcode decoding feature. Users can configure barcode decoding settings via this object.
• _cameraView: The camera view that displays the video stream (from a camera input).
• _cameraEnhancer: The object that enables you to control the camera.
• decodeResults: An object that will be used to receive and store barcode decoding results.

Add _configDBR method to initialize the barcode reader:

class _MyHomePageState extends State<MyHomePage> {
  ...
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
    _configDBR();
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    _cameraEnhancer.close();
    _barcodeReader.stopScanning();
    super.dispose();
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    super.didChangeAppLifecycleState(state);

    switch (state) {
      case AppLifecycleState.resumed:
        _barcodeReader.startScanning();
        _cameraEnhancer.open();
        break;
      case AppLifecycleState.inactive:
        _cameraEnhancer.close();
        _barcodeReader.stopScanning();
        break;
    }
  }

  _configDBR() async {
    /// Create an instance of barcode reader.
    _barcodeReader = await DCVBarcodeReader.createInstance();
    /// Create an instance of camera enhancer.
    _cameraEnhancer = await DCVCameraEnhancer.createInstance();

    /// When overlayVisible is set to true, the decoded barcodes will be highlighted with overlays.
    _cameraView.overlayVisible = true;

    /// Receive the barcode decoding results and store the result in object decodeResults
    _barcodeReader.receiveResultStream().listen((List<BarcodeResult> res) {
      if (mounted) {
        setState(() {
          decodeResults = res;
        });
      }
    });

    await _cameraEnhancer.open();

    /// Start barcode decoding when the widget is created.
    _barcodeReader.startScanning();
  }
}

Add configurations to parse and display the barcode decoding results:

class _MyHomePageState extends State<MyHomePage> {
  ...
  /// Get listItem
  Widget listItem(BuildContext context, int index) {
    BarcodeResult res = decodeResults[index];

    return ListTileTheme(
        textColor: Colors.white,
        child: ListTile(
          title: Text(res.barcodeFormatString),
          subtitle: Text(res.barcodeText),
        ));
  }
}

Build the Widget

Modify the build method to display the decode barcode results on the widget.

class _MyHomePageState extends State<MyHomePage> {
  ...
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('HelloWorld'),
      ),
      body: Stack(
        children: [
          Container(
            child: _cameraView,
          ),
          Container(
            height: 200,
            child: ListView.builder(
              itemBuilder: listItem,
              itemCount: decodeResults.length,
            ),
          ),
        ],
      ));
  }
}

Run the Project

Run Android on Windows

Go to the file build.gradle(app), update the minSdkVersion to 21.

android {
   defaultConfig {
      ...
      minSdkVersion 21
      ...
   }
}

In the root of your project run the following command to build and install the app:

flutter run

Run iOS on macOS

In the project folder, go to file ios/Runner/info.plist, add the following code for requesting camera permission:

<plist version="1.0">
<dict>
  ...
  <key>NSCameraUsageDescription</key>
  <string>Request your authorization.</string>
  ...
</dict>

Go to the Podfile in ios folder and add the following code at the top of the file:

platform:ios, '10.0'

In the root of your project run the following command to build and install the app:

flutter run

Samples

You can view all the DCV Flutter samples via the following links:

• Barcode reader simple sample

API References

View the API reference of DCV Flutter Edition to explore the full feature of DCV:

• DCV API Reference - Flutter Edition
  • DCVBarcodeReader Class
  • DCVCameraEnhancer Class
  • DCVCameraView Class

License

• You can also request an extension for your trial license in the customer portal

Contact

https://www.dynamsoft.com/company/contact/