IScanSession Interface Reference

Public Member Functions

void Clear ()
void PauseScanning ()
void StopScanning ()
void RejectCode (Barcode code)
void RejectTrackedCode (TrackedBarcode trackedCode)


NSArray< BarcodeNewlyRecognizedCodes [get]
NSArray< BarcodeNewlyLocalizedCodes [get]
NSArray< BarcodeAllRecognizedCodes [get]
NSDictionary< NSNumber, NSObject > TrackedCodes [get]

Detailed Description

Holds all barcodes that were decoded in the current session.

Configuring Session Behaviour

The scan session is responsible for determining the list of "relevant" barcodes by filtering out duplicates. Depending on your app, different duplicate removal is required. For some applications, only one barcode is required. The scanning process is stopped as soon as one code is decoded. For other applications, multiple codes are scanned after another. For example, a scanner at the cash desk may need to scan multiple products. To avoid duplicates, the same barcode should not be scanned in short succession. The same barcode (data, symbology) should not count as a duplicate if encountered again after a few seconds.

By default, if a barcode has the same symbology and data as code that was decoded less than 500ms ago, it is filtered out as a duplicate. The exact filtering behaviour can be changed by setting the "code duplicate filter", see ScanditBarcodeScanner.iOS.ScanSettings.CodeDuplicateFilter for details.

Session Lifetime

The session is cleared when ScanditBarcodeScanner.iOS.BarcodePicker.StartScanning is called, or when the user manually clears the session using ScanditBarcodeScanner.iOS.IScanSession.Clear.

Member Function Documentation

void Clear ( )

Remove all codes from the scan session.

Use this method to manually remove all codes from the scan session. Typicaly you will not have to this method directly but instead configure the duplicate removal and code caching duration with through ScanditBarcodeScanner.iOS.ScanSettings

void PauseScanning ( )

Immediately pauses barcode recognition, but keeps camera preview open.

This is useful for briefly pausing the barcode recognition to show the recognized code in an overlay and then resume the scan process to scan more codes.

When only scanning one code and then returning to another part of the application, it is recommended to call StopScanning instead.

Pausing will not clear the scan session. To remove all codes from the scan session call Clear.

void StopScanning ( )

Immediately stop barcode recognition and close camera.

Use this method when you finished scanning barcodes. In case you want to only briefly pause barcode recognition, use PauseScanning instead.

void RejectCode ( Barcode  code)

Prevent beeping/vibrate and highlighting for a particular code.

Use this method to reject a certain code if you have additional methods for verifying the integrity of the code, e.g. with a custom checksum. Rejected codes won't be highlighted in the scan UI. Additionally beep and vibration will be surpressed.

For this feature to work, you will have to enable code rejection by setting ScanSettings.CodeRejectionEnabled to true.

Rejected codes will be added to AllRecognizedCodes like all other codes.

Note that you should only pass codes returned by NewlyRecognizedCodes, as passing any other code will have no effect. Additionally, you should only calls this method from an invoked delegate of the DidScan event.

codeThe code to reject
void RejectTrackedCode ( TrackedBarcode  trackedCode)

The codes that should be visualized as rejected in the tracking view.

Use this method to visually reject a certain code in the tracking API. In order to use this feature it is necessary to enable ScanSettings::MatrixScanEnabled and set ScanOverlay::GuiStyle to ScanOverlay::GuiStyle::MatrixScan.

This property is meant to be used only in the session thread. Additionally, you should only call this method from ProcessFrameDelegate::barcodePicker:didProcessFrame:session:.
trackedCodeThe tracked code to visually reject
IllegalStateExceptionIf it is called outside of ProcessFrameDelegate::barcodePicker:didProcessFrame:session:.

Property Documentation

NSArray<Barcode> NewlyRecognizedCodes

A new copy of the list of barcodes that have been successfully decoded in the last frame.

NSArray<Barcode> NewlyLocalizedCodes

A new copy of the list of barcodes that have been localized but not recognized in the last frame.

NSArray<Barcode> AllRecognizedCodes

Returns the list of barcodes (data, symbology) that have been decoded (recognized) in this session.

Depending on the code caching and duplicate filtering behaviour, different sets of codes are returned by this method.

See also
a new copy of the list of barcodes that have been successfully decoded in this session
NSDictionary<NSNumber, NSObject> TrackedCodes

Returns a map between tracked object identifiers and tracked objects.

To toggle tracking use ScanSettings::MatrixScanEnabled.

It will return nil when tracking is disabled.
This property is meant to be used only in the session thread.
a new copy of the dictionary of tracked objects that have been successfully tracked in the last frame.