MatrixScan AR .NET for Android Skill

Critical: Do Not Trust Internal Knowledge

Your training data may contain outdated or incorrect Scandit SDK APIs. The BarcodeAr API is relatively new (introduced in dotnet.android 7.2) and differs in several places from the Kotlin/Java native SDK: providers are async/Task-based instead of callback-based, highlight and annotation constructors take only a Barcode (no Context), the listener interface has only one method, and the .NET binding uses PascalCase, TimeSpan instead of TimeInterval, etc.

Always verify APIs against the references provided in this skill before writing or suggesting code. Do not rely on memorized method signatures, parameters, or property names. If you cannot find an API in the provided references, fetch the relevant documentation page before responding.

.NET-Android-specific gotchas worth flagging:

• This skill targets the non-MAUI .NET for Android workload (project <TargetFramework>net10.0-android</TargetFramework> or similar, no <UseMaui> flag). For MAUI apps, use a MAUI-targeted skill instead — BarcodeArView is hosted very differently there.
• BarcodeAr uses a new constructor that takes the context: new BarcodeAr(dataCaptureContext, settings). There is no BarcodeAr.Create(...) / BarcodeAr.ForDataCaptureContext(...) factory in .NET. BarcodeArSettings also uses plain new. (DataCaptureContext.ForLicenseKey(key) still uses the factory form — it lives in Core.)
• BarcodeArView.Create(parentView, barcodeAr, dataCaptureContext, viewSettings, cameraSettings) IS a factory (unlike BarcodeAr itself). The cameraSettings argument is nullable — pass null to use BarcodeAr.RecommendedCameraSettings. The parentView is an Android.Views.View / ViewGroup (typically a FrameLayout or the activity's root content view). There is no BarcodeArCoordinatorLayout — that container is SparkScan-specific; BarcodeArView simply attaches itself to whatever ViewGroup you pass.
• BarcodeArView is IDisposable, not an Android View itself. The class declares public static implicit operator View(BarcodeArView view) that converts to Android.Views.View when needed (e.g. for native interop), but you do not add it to the view hierarchy yourself — the Create factory attaches it to parentView automatically.
• Lifecycle on the view is barcodeArView.OnResume() / barcodeArView.OnPause() — these are Android-only methods (guarded by #if ANDROID in the binding) and they are not the activity's OnPause/OnResume. Forward the activity calls into them. OnDestroy() does not exist on the .NET BarcodeArView — call Dispose() instead (in the activity's OnDestroy or Dispose).
• IBarcodeArListener has only one method: OnSessionUpdated(BarcodeAr, BarcodeArSession, IFrameData). There are no OnObservationStarted / OnObservationStopped callbacks like the Kotlin BarcodeArListener has. Implementing those will produce compile errors — the interface simply does not declare them.
• Prefer the event API (barcodeAr.SessionUpdated += handler) over the listener interface in idiomatic C#. The handler receives BarcodeArEventArgs with BarcodeAr, Session, and FrameData. AddListener(IBarcodeArListener) still works for parity with other platforms.
• OnSessionUpdated / SessionUpdated runs on a background recognition thread. Dispatch any UI update via RunOnUiThread(() => { … }).
• Provider interfaces are async, not callback-based. IBarcodeArHighlightProvider.HighlightForBarcodeAsync(Barcode) returns Task<IBarcodeArHighlight?> and IBarcodeArAnnotationProvider.AnnotationForBarcodeAsync(Barcode) returns Task<IBarcodeArAnnotation?>. Do not look for a Callback parameter or a callback.OnData(...) method — they don't exist in the .NET binding. Return Task.FromResult<IBarcodeArHighlight?>(null) (or null from an async method) to suppress the highlight/annotation for a given barcode.
• Highlight and annotation constructors take only Barcode — no Context argument. Use new BarcodeArRectangleHighlight(barcode), new BarcodeArCircleHighlight(barcode, BarcodeArCircleHighlightPreset.Dot), new BarcodeArInfoAnnotation(barcode), new BarcodeArStatusIconAnnotation(barcode), new BarcodeArPopoverAnnotation(barcode, buttons). Passing a Context is a compile error.
• Symbology names are C# PascalCase: Symbology.Ean13Upca, Symbology.Ean8, Symbology.Code128, Symbology.Code39, Symbology.Qr, Symbology.DataMatrix, Symbology.InterleavedTwoOfFive. They are not the Kotlin underscore style (EAN13_UPCA).
• BarcodeArSettings does not expose an Enabled toggle — BarcodeAr itself has no Enabled property either. To pause/resume scanning, use barcodeArView.Pause() / barcodeArView.Start().
• BarcodeArViewSettings is minimal in .NET. Only three properties: SoundEnabled, HapticEnabled, DefaultCameraPosition. Do not invent properties like TriggerButtonCollapseTimeout, InactiveStateTimeout, ToastSettings, or DefaultMiniPreviewSize — those are SparkScan, not BarcodeAr.
• BarcodeArFeedback lives in Scandit.DataCapture.Barcode.Ar.Feedback and has two Core.Common.Feedback.Feedback properties: Scanned and Tapped. The empty constructor new BarcodeArFeedback() produces a feedback object with both events silent — assigning it to barcodeAr.Feedback disables the default beep/vibration. To restore defaults, use the static BarcodeArFeedback.DefaultFeedback. (Note: it's a static property in .NET, not the Kotlin BarcodeArFeedback.defaultFeedback() method.)
• Tap interactions on highlights are exposed as the HighlightForBarcodeTapped event on BarcodeArView (EventHandler<HighlightForBarcodeTappedEventArgs>). There is no UiListener property on the .NET BarcodeArView — the Kotlin IBarcodeArViewUiListener is surfaced as a C# event instead. Event args expose BarcodeAr, Barcode, and Highlight.
• barcodeAr.Feedback is a property (get/set); ApplySettingsAsync(BarcodeArSettings) returns a Task. BarcodeAr.RecommendedCameraSettings is a static property, not a method (the Kotlin SDK exposes BarcodeAr.createRecommendedCameraSettings() — in .NET it's a getter).
• No BarcodeArFilter / SetBarcodeFilter in the .NET API tree. The Kotlin/iOS setBarcodeFilter(...) method (added in 8.1) is not surfaced on dotnet.android at present. Do not attempt to use it.
• SDK 8.0+ requires explicit initialization. Subclass Android.App.Application, decorate with [Application], and call ScanditCaptureCore.Initialize() + ScanditBarcodeCapture.Initialize() in OnCreate() before any Scandit code runs. Without this, the first new BarcodeAr(...) / BarcodeArView.Create(...) call crashes at launch because the DI container has no registrations. Not required on 6.x / 7.x. See [references/integration.md](references/integration.md) for the full MainApplication.cs template.
• The NuGet packages are Scandit.DataCapture.Core and Scandit.DataCapture.Barcode. No separate *.Maui packages here — those are only for MAUI projects. Do not guess the version from training data — fetch the latest stable from https://www.nuget.org/packages/Scandit.DataCapture.Barcode/ via WebFetch before pinning. Inventing a non-existent version (e.g. 8.13.0 when only 8.4.0 is published) causes dotnet restore to fail with Unable to find package Scandit.DataCapture.Core with version (>= …). See [references/integration.md](references/integration.md) Step 0 for the full procedure.
• Android SupportedOSPlatformVersion must be ≥ 24. Set it in the .csproj. Lower values fail the build with uses-sdk:minSdkVersion 21 cannot be smaller than version 24 declared in library.
• Do not declare <activity> elements for [Activity]-decorated classes in AndroidManifest.xml. The [Activity(MainLauncher = true, ...)] attribute is the canonical registration mechanism in .NET for Android — the build merges a correctly-named entry into the final manifest using the .NET-derived Java class name. A manual <activity android:name=".MainActivity"> resolves against <ApplicationId> and won't match the generated class, producing ClassNotFoundException: Didn't find class ... .MainActivity at launch. Only add to the manifest the elements the skill explicitly asks for (<uses-feature>, <uses-permission>) — leave activities to the attribute.
• The runtime camera permission helper (CameraPermissionActivity) inherits from AppCompatActivity, so Xamarin.AndroidX.AppCompat must be in the .csproj. When pinning the version, pick the highest available including the Xamarin patch revision (e.g. 1.7.0.5, not bare 1.7.0) — the .X suffix marks Xamarin-binding-level updates and carries critical transitive-dep fixes.
• The activity needs a Theme.AppCompat descendant. Because the activity inherits from AppCompatActivity, set Theme = "@style/Theme.AppCompat.Light.NoActionBar" on the [Activity] attribute (or android:theme=... on <application> in the manifest). Without it, SetContentView throws IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity at launch. The dotnet new android template's default theme is not AppCompat-based, so this must be set explicitly.

Intent Routing

Based on the user's request, load the appropriate reference file before responding:

• Integrating BarcodeAr from scratch, configuring settings, customizing highlights or annotations, handling session updates, customizing feedback, or wiring tap interactions (e.g. "add MatrixScan AR to my .NET Android app", "set up barcode AR scanning in C#", "show a rectangle highlight on every tracked barcode", "show an info annotation with the barcode data", "make the beep silent", "react to a highlight tap", "switch to circle highlights") → read [references/integration.md](references/integration.md) and follow the instructions there.
• Migrating or upgrading an existing MatrixScan AR integration (e.g. "upgrade from v7 to v8", "bump the Scandit .NET SDK to v8", "what changed between SDK versions for BarcodeAr", "do I need to change my BarcodeAr code when moving to 8.x") → read [references/migration.md](references/migration.md) and follow the instructions there.

API Usage Policy

Only use APIs that are explicitly documented in the Scandit references below. Do not invent or guess method signatures, parameters, or property names. If unsure whether an API exists or how it is called — or if a compile error occurs — fetch the relevant reference page before responding. Do not tell the user to check the docs themselves. After answering, always include the relevant link so the user can explore further.

Never construct or guess documentation URLs. When you need a specific class or property's API page:

1. First check whether the page you already fetched contains a direct hyperlink to it — topic pages link directly to relevant API symbols. Always request links alongside content in your fetch prompt.
2. If no direct link was found, fetch the API index (see Full API reference in the table below), extract the actual link from it, and follow that.

URL structures can vary (e.g. api/ui/ subdirectory) and guessing will lead to 404s.

References

Direct users to the right resource based on their question:

API surface this skill covers

All classes documented with :available: dotnet.android in the official RST docs (docs/source/barcode-capture/api/barcode-ar.rst and api/ui/barcode-ar-.rst) are addressed in [references/integration.md](references/integration.md):

• BarcodeAr — new BarcodeAr(DataCaptureContext?, BarcodeArSettings), Feedback (get/set), ApplySettingsAsync(BarcodeArSettings) → Task, AddListener(IBarcodeArListener) / RemoveListener(IBarcodeArListener), event EventHandler<BarcodeArEventArgs> SessionUpdated, static RecommendedCameraSettings, Dispose.
• BarcodeArSettings — new BarcodeArSettings(), EnableSymbology(Symbology, bool), EnableSymbologies(ICollection<Symbology>), GetSymbologySettings(Symbology), EnabledSymbologies (get), ExpectsOnlyUniqueBarcodes (get/set), SetProperty / GetProperty<T> / TryGetProperty<T>, Dispose.
• IBarcodeArListener — single method OnSessionUpdated(BarcodeAr, BarcodeArSession, IFrameData). (No OnObservation* callbacks.)
• BarcodeArSession — AddedTrackedBarcodes (IReadOnlyList<TrackedBarcode>), RemovedTrackedBarcodes (IReadOnlyList<int>), TrackedBarcodes (IReadOnlyDictionary<int, TrackedBarcode>), Reset().
• BarcodeArEventArgs — BarcodeAr, Session, FrameData.
• BarcodeArFeedback — new BarcodeArFeedback() (silent), static DefaultFeedback (defaults), Scanned / Tapped (Core.Common.Feedback.Feedback), Dispose.
• BarcodeArView — static Create(View parentView, BarcodeAr, DataCaptureContext, BarcodeArViewSettings, CameraSettings?), HighlightProvider (get/set IBarcodeArHighlightProvider?), AnnotationProvider (get/set IBarcodeArAnnotationProvider?), ShouldShowTorchControl / ShouldShowZoomControl / ShouldShowCameraSwitchControl, TorchControlPosition / ZoomControlPosition / CameraSwitchControlPosition (Anchor), Start(), Stop(), Pause(), Reset(), GetNotificationPresenter(), OnResume() / OnPause() (Android-only), event EventHandler<HighlightForBarcodeTappedEventArgs> HighlightForBarcodeTapped, implicit conversion to Android.Views.View, Dispose.
• BarcodeArViewSettings — SoundEnabled (default true), HapticEnabled (default true), DefaultCameraPosition (default WorldFacing).
• HighlightForBarcodeTappedEventArgs — BarcodeAr, Barcode, Highlight (IBarcodeArHighlight).
• Highlights: IBarcodeArHighlight : IDisposable, IBarcodeArHighlightProvider.HighlightForBarcodeAsync(Barcode) → Task<IBarcodeArHighlight?>, BarcodeArRectangleHighlight(Barcode) with Barcode / Brush / Icon, BarcodeArCircleHighlight(Barcode, BarcodeArCircleHighlightPreset) with Barcode / Brush / Icon / Size, BarcodeArCircleHighlightPreset enum (Dot, Icon).
• Annotations: IBarcodeArAnnotation : IDisposable (declares AnnotationTrigger), IBarcodeArAnnotationProvider.AnnotationForBarcodeAsync(Barcode) → Task<IBarcodeArAnnotation?>.

- BarcodeArStatusIconAnnotation(Barcode) — AnnotationTrigger, HasTip, Icon, Text, TextColor, BackgroundColor. - BarcodeArInfoAnnotation(Barcode) — HasTip, EntireAnnotationTappable, Anchor (BarcodeArInfoAnnotationAnchor), AnnotationTrigger, Width (BarcodeArInfoAnnotationWidthPreset), Body (IReadOnlyCollection<BarcodeArInfoAnnotationBodyComponent>), Header (BarcodeArInfoAnnotationHeader?), Footer (BarcodeArInfoAnnotationFooter?), BackgroundColor, Listener (IBarcodeArInfoAnnotationListener?). - BarcodeArPopoverAnnotation(Barcode, IList<BarcodeArPopoverAnnotationButton>) — AnnotationTrigger, EntirePopoverTappable, Listener (IBarcodeArPopoverAnnotationListener?), Buttons. - BarcodeArPopoverAnnotationButton(ScanditIcon, string) — Text, TextSize, Typeface, TextColor, Enabled, Icon. - BarcodeArAnnotationTrigger enum: HighlightTapAndBarcodeScan, HighlightTap.

• Info-annotation sub-package (Scandit.DataCapture.Barcode.Ar.UI.Annotations.Info): BarcodeArInfoAnnotationBodyComponent (Text, TextColor, TextSize, Typeface, StyledTextFormatted, LeftIcon, RightIcon, LeftIconTappable, RightIconTappable, TextAlignment), BarcodeArInfoAnnotationHeader (Text, TextSize, Typeface, TextColor, Icon, BackgroundColor), BarcodeArInfoAnnotationFooter (Text, TextSize, Typeface, TextColor, Icon, BackgroundColor), BarcodeArInfoAnnotationAnchor enum (Left, Right, Bottom, Top), BarcodeArInfoAnnotationWidthPreset enum (Small, Medium, Large), IBarcodeArInfoAnnotationListener (OnInfoAnnotationHeaderTapped, OnInfoAnnotationFooterTapped, OnInfoAnnotationLeftIconTapped, OnInfoAnnotationRightIconTapped, OnInfoAnnotationTapped).
• IBarcodeArPopoverAnnotationListener — OnPopoverButtonTapped, OnPopoverTapped.
• TrackedBarcode (in Scandit.DataCapture.Barcode.Batch.Data) — Barcode, Identifier, Location.