BarcodeReadSymbologyOperation Enumeration

Summary

Current barcode read operation.

Syntax

Objective-C

C++/CLI

Java

Python

[SerializableAttribute()] 
public enum BarcodeReadSymbologyOperation

typedef NS_ENUM(NSInteger, LTBarcodeReadSymbologyOperation) { 
 LTBarcodeReadSymbologyOperationPreRead,  
 LTBarcodeReadSymbologyOperationPostRead 
};

public enum BarcodeReadSymbologyOperation

[SerializableAttribute()] 
public enum class BarcodeReadSymbologyOperation

class BarcodeReadSymbologyOperation(Enum): 
   PreRead = 0 
   PostRead = 1

Members

Value	Member	Description
0	PreRead	The BarcodeReader object is about to read the barcode symbologies. The input parameters are: The symbologies to be read which can be obtained through the GetSymbologies method and the associated read options that are in the Options property.
1	PostRead	The BarcodeReader has finished reading the barcode symbologies. The input parameters are: The symbologies to be read which can be obtained through the GetSymbologies method and the associated read options that are in the Options property. The resulting parameters are: The barcode data found which is in the Data property that may contain a valid BarcodeData object or null (Nothing in Visual Basic) when an error occurs or no barcode of this type is found. In case of an error, the exception is in the Error property (Refer to BarcodeReader.ErrorMode for more information).

Value

Member

Description

PreRead

The BarcodeReader object is about to read the barcode symbologies.

The input parameters are: The symbologies to be read which can be obtained through the GetSymbologies method and the associated read options that are in the Options property.

PostRead

The BarcodeReader has finished reading the barcode symbologies.

The input parameters are: The symbologies to be read which can be obtained through the GetSymbologies method and the associated read options that are in the Options property.

The resulting parameters are: The barcode data found which is in the Data property that may contain a valid BarcodeData object or null (Nothing in Visual Basic) when an error occurs or no barcode of this type is found. In case of an error, the exception is in the Error property (Refer to BarcodeReader.ErrorMode for more information).

Remarks

This enumeration is used as the type for the BarcodeReadSymbologyEventArgs.Operation property that can be used to determine the current barcode read stage.

Example

Java

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Barcode; 
using Leadtools.ImageProcessing; 
 
 
public void BarcodeReader_ReadSymbologyExample() 
{ 
   string imageFileName = Path.Combine(LEAD_VARS.ImagesDir, "Barcode1.tif"); 
 
   // Create a Barcode engine 
   BarcodeEngine engine = new BarcodeEngine(); 
 
   // Get the Barcode reader instance 
   BarcodeReader reader = engine.Reader; 
          
   // Load the image 
   using (RasterCodecs codecs = new RasterCodecs()) 
   { 
      using (RasterImage image = codecs.Load(imageFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1)) 
      { 
         // Subscribe to the ReadSymbology event 
         reader.ReadSymbology += new EventHandler<BarcodeReadSymbologyEventArgs>(reader_ReadSymbology); 
         // Read all barcodes in the image 
         reader.ReadBarcodes(image, LeadRect.Empty, 0, null); 
         reader.ReadSymbology -= new EventHandler<BarcodeReadSymbologyEventArgs>(reader_ReadSymbology); 
      } 
   } 
} 
 
private void reader_ReadSymbology(object sender, BarcodeReadSymbologyEventArgs e) 
{ 
   if (e.Operation == BarcodeReadSymbologyOperation.PreRead) 
   { 
      // Before reading, show the symbologies the engine is going to try to read 
      Console.WriteLine("Trying to read the following symbologies:"); 
      BarcodeSymbology[] symbologies = e.GetSymbologies(); 
      for (int i = 0; i < symbologies.Length; i++) 
      { 
         Console.Write(symbologies[i]); 
         if (i != (symbologies.Length - 1)) 
         { 
            Console.Write(", "); 
            Console.WriteLine(e.Options.FriendlyName); 
         } 
         else 
         { 
            Console.WriteLine(); 
         } 
      } 
   } 
   else if (e.Operation == BarcodeReadSymbologyOperation.PostRead) 
   { 
      if (e.Error == null) 
      { 
         // No errors 
         BarcodeData barcode = e.Data; 
         if (barcode != null) 
         { 
            // Found a barcode, show it 
            Console.WriteLine("  {0} at {1} with data {2}", barcode.Symbology, barcode.Bounds, barcode.Value); 
         } 
         else 
         { 
            Console.WriteLine("  No barcodes found"); 
         } 
      } 
      else 
      { 
         // Show the error 
         Console.WriteLine("Error: {0}", e.Error.Message); 
 
         // Tell the reader top stop reading barcodes 
         e.Status = BarcodeReadSymbologyStatus.Abort; 
      } 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}

 
import java.io.File; 
import java.io.IOException; 
import java.util.*; 
import java.util.concurrent.ExecutorService; 
import java.util.concurrent.Executors; 
 
import org.junit.*; 
import org.junit.Test; 
import org.junit.runner.JUnitCore; 
import org.junit.runner.Result; 
import org.junit.runner.notification.Failure; 
import static org.junit.Assert.*; 
 
import leadtools.*; 
import leadtools.barcode.*; 
import leadtools.codecs.*; 
import leadtools.imageprocessing.*; 
import leadtools.internal.ManualResetEvent; 
 
 
public void barcodeReaderReadSymbologyExample() { 
   final String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images"; 
   String imageFileName = combine(LEAD_VARS_IMAGES_DIR, "barcode1.tif"); 
 
   // Create a Barcode engine 
   BarcodeEngine engine = new BarcodeEngine(); 
 
   // Get the Barcode reader instance 
   BarcodeReader reader = engine.getReader(); 
 
   // Load the image 
   RasterCodecs codecs = new RasterCodecs(); 
 
   RasterImage image = codecs.load(imageFileName, 0, CodecsLoadByteOrder.BGR_OR_GRAY, 1, 1); 
   codecs.save(image, "Result.jpg", RasterImageFormat.JPEG, 0); 
 
   // Subscribe to the ReadSymbology event 
   reader.addReadSymbologyListener(readerReadSymbology); 
 
   // Read all barcodes in the image 
   reader.readBarcodes(image, LeadRect.getEmpty(), 0, null); 
   reader.removeReadSymbologyListener(readerReadSymbology); 
 
   assertTrue("Image unsuccessfully saved", (new File("Result.jpg")).exists()); 
   System.out.printf("Image loaded and saved to %s%n", new File("Result.jpg")); 
} 
 
BarcodeReadSymbologyListener readerReadSymbology = new BarcodeReadSymbologyListener() { 
 
   @Override 
   public void onReadSymbologyEvent(BarcodeReadSymbologyEvent arg0) { 
 
      if (arg0.getOperation() == BarcodeReadSymbologyOperation.PRE_READ) { 
 
         // Before reading, show the symbologies the engine is going to try to read 
         System.out.println("Trying to read the following symbologies:"); 
         BarcodeSymbology[] symbologies = arg0.getSymbologies(); 
 
         for (int i = 0; i < symbologies.length; i++) { 
            System.out.print(symbologies[i]); 
 
            if (i != (symbologies.length - 1)) { 
               System.out.print(", "); 
               System.out.println(arg0.getOptions().getFriendlyName()); 
 
            } else { 
               System.out.println(" "); 
            } 
         } 
      } 
 
      else if (arg0.getOperation() == BarcodeReadSymbologyOperation.POST_READ) { 
 
         if (arg0.getError() == null) { 
 
            // No errors 
            BarcodeData barcode = arg0.getData(); 
 
            if (barcode != null) { 
 
               // Found a barcode, show it 
               System.out.printf("  %1s at %2s with data %3s%n", barcode.getSymbology(), barcode.getBounds(), 
                     barcode.getValue()); 
            } else { 
               System.out.println("  No barcodes found"); 
            } 
         } else { 
            // Show the error 
            System.out.printf("Error: %1s%n", arg0.getError().getMessage()); 
 
            // Tell the reader top stop reading barcodes 
            arg0.setStatus(BarcodeReadSymbologyStatus.ABORT); 
         } 
      } 
   } 
 
};

Requirements

Target Platforms

Reference

Leadtools.Barcode Namespace

BarcodeReader.ReadSymbology

BarcodeReader.ReadBarcode

BarcodeReader.ReadBarcodes

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Help Version 23.0.2024.2.29

Leadtools.Barcode Assembly

Introduction

Getting Started

Namespaces

Leadtools.Barcode Namespace

Assemblies