DCVBarcodeReader Class

A barcode reader object accesses to a camera via DCVCameraView object at native level, then perform continuous barcode scanning on the incoming frames.

Methods	Description
`initLicense`	Initialize the license of the Dynamsoft Barcode Reader module.
`createInstance`	Create a barcode reader instance.
`getVersion`	Get the version of `DCVBarcodeReader`, which is packaged in Dynamsoft Capture Vision.
`getRuntimeSettings`	Get the current runtime settings of `DCVBarcodeReader`.
`updateRuntimeSettings`	Update the runtime settings of `DCVBarcodeReader` with a `DBRRuntimeSettings` struct or a template.
`resetRuntimeSettings`	Reset the runtime settings of `DCVBarcodeReader` to default.
`outputRuntimeSettingsToString`	Output the runtime settings of `DCVBarcodeReader` to string.
`startScanning`	Start the barcode decoding thread.
`stopScanning`	Stop the barcode decoding thread.
`addResultListener`	Specifies an event handler that fires after the library finishes scanning a frame.
`removeAllResultListeners`	Remove all existing result listener.
`decodeFile`	Decode barcodes from a specified image file.
`enableDuplicateFilter`	Enable (or disable) duplicate result filter to get unique results from the result callback.

initLicense

Initialize the license of Dynamsoft Capture Vision - Barcode Reader Module.

static initLicense(license: String): Promise<void>;

Parameters

license: A license key.

Code Snippet

try {
  await DCVBarcodeReader.initLicense("DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9")
} catch (e) {
  // Catch and log the error message when license activation is failed.
  console.log(e)
}

createInstance

Create a barcode reader instance.

static createInstance(): Promise<DCVBarcodeReader>

Return Value

A barcode reader instance.

Code Snippet

this.reader = await DCVBarcodeReader.createInstance();

getVersion

Get the version of DCVBarcodeReader, which is packaged in Dynamsoft Capture Vision.

getVersion(): Promise<string>

Return Value

The Version of DCVBarcodeReader.

Code Snippet

let dbrVersion = await this.reader.getVersion();

getRuntimeSettings

Get the current runtime settings of DCVBarcodeReader. To learn more about the currently available runtime settings, please visit DBRRuntimeSettings interface page.

getRuntimeSettings(): Promise<DBRRuntimeSettings>

Return Value

An object that stores the runtime settings.

Code Snippet

let settings = await this.reader.getRuntimeSettings();

updateRuntimeSettings

Update the barcode decoding settings with a DBRRuntimeSettings struct, a preset template (from the EnumDBRPresetTemplate items) or a JSON String.

updateRuntimeSettings(settings: DBRRuntimeSettings | EnumDBRPresetTemplate | String): Promise<boolean>

Parameters

Settings: The parameter should be one of the following types:

settings (DBRRuntimeSettings): An object that stores DBRRuntimeSettings.
settings (EnumDBRPresetTemplate): One of the EnumDBRPresetTemplate member that indicates a preset template.
settings (String): A stringified JSON data that contains barcode decoding settings. The available settings include but not limited in DBRRuntimeSettings. You can access full feature of DBR when upload the settings from a JSON data.

Code Snippet

/* How to update runtime settings using runtime settings object */
let settings = await this.reader.getRuntimeSettings();
settings.barcodeFormatIds = EnumBarcodeFormat.BF_ONED | EnumBarcodeFormat.BF_QR_CODE;
settings.expectedBarcodeCount = 1;
await this.reader.updateRuntimeSettings(settings);

/* How to update using one of the preset templates */
await this.reader.updateRuntimeSettings(EnumDBRPresetTemplate.VIDEO_SPEED_FIRST);

/* How to update the settings using a JSON string */
await this.reader.updateRuntimeSettings("{\"ImageParameter\":{\"BarcodeFormatIds\":[\"BF_ALL\"],\"BarcodeFormatIds_2\":null,\"DeblurLevel\":0,\"ExpectedBarcodesCount\":0,\"LocalizationModes\":[{\"Mode\":\"LM_SCAN_DIRECTLY\",\"ScanDirection\":1},{\"Mode\":\"LM_CONNECTED_BLOCKS\"}],\"Name\":\"video-speed-first\",\"ScaleDownThreshold\":2300,\"Timeout\":500},\"Version\":\"3.0\"}")

resetRuntimeSettings

Reset the barcode decoding settings.

resetRuntimeSettings(): Promise<boolean>

Code Snippet

await this.reader.resetRuntimeSettings();

outputRuntimeSettingsToString

Output the barcode decoding settings to string.

outputRuntimeSettingsToString(): Promise<string>

Return Value

A string that stores the barcode decoding settings. The barcode settings string can be applied to debug barcode decoding settings.

Code Snippet

let settingString = await this.reader.outputRuntimeSettingsToString();

startScanning

Start the barcode decoding thread.

startScanning(): Promise<void>

Code Snippet

await this.reader.startScanning();

stopScanning

Stop the barcode decoding thread.

stopScanning(): Promise<void>

Code Snippet

await this.reader.stopScanning();

addResultListener

Specifies an event handler that fires after the library finishes scanning a frame.

addResultListener(listener: (results: BarcodeResult[]) => void): void

Parameters

listener: The event listener that handles callback when barcode result is returned by the library.

Code Snippet

state = {
  results: null
};
componentDidMount() {
  (async () => {
    try {
      await DCVBarcodeReader.initLicense("DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9")
    } catch (e) {
      console.log(e);
    }
    this.reader = await DCVBarcodeReader.createInstance();
    await this.reader.startScanning();
    this.reader.addResultListener((results) => {
      this.setState({results});
    });
  })();
}

removeAllResultListeners

Remove all existing result listener.

removeAllResultListeners(): void;

Code Snippet

async componentWillUnmount() {
  ...
  // Remove the result listener when your component is unmount.
  this.reader.removeAllResultListeners()
}

decodeFile

Decode barcodes from an image file.

decodeFile(filePath: string): Promise<BarcodeResult[]>;

Parameters

filePath: The Path of the image file.

Code Snippet

try {
  await DCVBarcodeReader.initLicense("DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9")
} catch (e) {
  console.log(e);
}
reader = await DCVBarcodeReader.createInstance();
result = reader.decodeFile("Your file path");

enableDuplicateFilter

Enable (or disable) duplicate result filter to get unique results from the result callback.

enableDuplicateFilter(isEnabled: boolean): Promise<void>;

Parameters

isEnabled: A boolean value that determines whether to enable the result deduplication. Set it to true when you want to enable the filter. Otherwise, set it to false.