CameraScanner.Maui

This library offers camera preview and barcode scanning functionality for .NET MAUI apps using native platform APIs with Google ML Kit and Apple VisionKit.

Download and Install CameraScanner.Maui

This library is available on NuGet: https://www.nuget.org/packages/CameraScanner.Maui Use the following command to install Plugin.FirebasePushNotifications using NuGet package manager console:

PM> Install-Package CameraScanner.Maui

You can use this library in any .NET MAUI project compatible to .NET 8 and higher.

App Setup

1. This plugin provides an extension method for MauiAppBuilder UseCameraScanner which ensure proper startup and initialization. Call this method within your MauiProgram just as demonstrated in the CameraDemoApp:

   var builder = MauiApp.CreateBuilder()
       .UseMauiApp<App>()
       .UseCameraScanner();

2. Add camera permission for Android in your AndroidManifest.xml file. Add the following uses-permission entry inside of the manifest node:

   <uses-permission android:name="android.permission.CAMERA" />

3. Add camera permission for iOS in your Info.plist file. Add the following permission inside of the dict node:

   <key>NSCameraUsageDescription</key>
   <string>Required to display camera preview and scan barcodes.</string>

   Permission strings can also be localized on iOS using lproj-folders and InfoPlist.strings files. Read this if you're interested in this topic.

API Usage

The following documentation guides you trough the most important use cases of this library. Not all aspects are covered. If you think there is something important missing here, feel free to open a new issue.

This documentation only demonstrates the use of CameraScanner.Maui within a XAML and MVVM based app. Of course, the code also runs in C# and code-behind UIs.

Use CameraView in XAML

In order to add the camera preview control CameraView to your xaml page, you need to add the xml namespace in the root of your xaml file:

xmlns:c="http://camerascanner.maui"

Then, you can add CameraView to your xaml UI.

<c:CameraView />

There are several bindable properties in CameraView in order to configure and control the camera preview.

Configure CameraView

Property	Description
AutoDisconnectHandler	Defines if the platform handler is automatically disconnected or if Handler.DisconnectHandler(); is called manually. Default: true (automatically disconnected)
VibrationOnDetected	Enables or disables vibration on successful barcode detection. Default: false
CameraEnabled	Enables or disables the camera preview. Default: true
PauseScanning	Pauses barcode scanning.
ForceInverted	Forces scanning of inverted barcodes. Reduces performance significantly. Android only.
PoolingInterval	Enables pooling of detections for better detection of multiple barcodes at once. Value in milliseconds. Default: 0 (disabled).
TorchOn	Enables or disables the torch.
TapToFocusEnabled	Disables or enables tap-to-focus.
CameraFacing	Select front or back facing camera. Default: CameraFacing.Back
CaptureQuality	Set the capture quality for the image analysis. Recommended and default value is Medium. Use the highest values for more precision or lower for fast scanning.
BarcodeFormats	Set the enabled barcode formats. Default: BarcodeFormats.All.
AimMode	Disables or enables aim mode. When enabled only barcode that is in the center of the preview will be detected.
ViewfinderMode	Disables or enables viewfinder mode. When enabled only barcode that is visible in the preview will be detected.
CaptureNextFrame	Captures the next frame from the camera feed.
BarcodeDetectionFrameRate	Specifies the frequency at which frames are processed for barcode detection. Default: null (no frame skipping) Example: If the value is null, 0 or 1, every frame from the camera preview is analyzed. If the value is 2, every 2nd frame from the camera preview is analyzed. If the value is 3, every 3rd frame from the camera preview is analyzed.
RequestZoomFactor	Setting this value changes the zoom factor of the camera. Value has to be between MinZoomFactor and MaxZoomFactor. More info: iOS/macOS - https://developer.apple.com/documentation/avfoundation/avcapturedevice/zoom Android - https://developer.android.com/reference/kotlin/androidx/camera/view/CameraController#setZoomRatio(float) Only logical multi-camera is supported - https://developer.android.com/media/camera/camera2/multi-camera
CurrentZoomFactor	Returns current zoom factor value.
MinZoomFactor	Returns minimum zoom factor for current camera.
MaxZoomFactor	Returns maximum zoom factor for current camera.
DeviceSwitchZoomFactors	Returns zoom factors that switch between camera lenses. Supported on iOS only.

Ask for camera permission

Before your app is allowed to access the camera stream, the user has to give runtime permission to access the camera. This library provides the interface ICameraPermissions to check if the permission is already given and/or to ask for permission.

Access ICameraPermissions via static singleton instance CameraPermissions.Current or inject it using dependency injection.

• IBarcodeScanner tbd

Supported Barcode Formats

The following barcode formats are supported on the underlying platforms:

Barcode Format	Supported on iOS	Supported on Android
Aztec	✅	✅
Code128	✅	✅
Code39	✅	✅
Code93	✅	✅
DataMatrix	✅	✅
Ean13	✅	✅
Ean8	✅	✅
ITF	✅	✅
Pdf417	✅	✅
QR	✅	✅
UPC_A	✅	✅
UPC_E	✅	✅
Codabar	✅ *1)	✅
GS1DataBar	✅ *1)	⬜
GS1DataBarExpanded	✅ *1)	⬜
GS1DataBarLimited	✅ *1)	⬜
I2of5	✅	⬜
MicroQR	✅ *1)	⬜
MicroPdf417	✅ *1)	⬜

*1) Supported on iOS 15 and later.

Contribution

Contributors welcome! If you find a bug or you want to propose a new feature, feel free to do so by opening a new issue on github.com.

Links

• https://developers.google.com/ml-kit/vision/barcode-scanning
• https://developer.apple.com/documentation/visionkit
• https://orcascan.com/tools/free-barcode-generator
• https://barcode.tec-it.com/