QRBarcodeData Class

Summary

Contains the data for a single QR barcode.

Syntax

Objective-C

C++/CLI

Java

Python

[SerializableAttribute()] 
public class QRBarcodeData : BarcodeData

@interface LTQRBarcodeData : LTBarcodeData<NSCopying>

public class QRBarcodeData extends BarcodeData

[TypeConverterAttribute()] 
[SerializableAttribute()] 
public ref class QRBarcodeData : public BarcodeData, System.ICloneable

class QRBarcodeData(BarcodeData):

Remarks

The QRBarcodeData class derives from the base BarcodeData to add specific data that can be read or written when using QR barcodes.

Reading Barcodes

When the BarcodeReader object detects and reads a QR (BarcodeSymbology.QR ), the BarcodeReader.ReadBarcode and BarcodeReader.ReadBarcodes methods will return the QRBarcodeData object for each barcode cast down to the base BarcodeData class.

Perform standard .NET casting to get the object as QRBarcodeData and then examine the extra data properties associated with it.

In addition to all the data members returned as usual in the base BarcodeData object, this class adds the following members:

SymbolModel
A QRBarcodeSymbolModel enumeration member that specifies the symbol model and version of the QR barcode.

In addition to the members above, other QR read options not related to the barcode data can be set using the QRBarcodeReadOptions class.

Writing Barcodes

The BarcodeWriter class contains the WriteBarcode method that is used to write a barcode to an image. This method accepts the data parameter as the base BarcodeData object. To write a QR barcode, create an instance of QRBarcodeData and fill the required parameters then pass this object as the data parameter to WriteBarcode.

In addition to all the data members that must be set as usual in the base BarcodeData object, specify the following members:

SymbolModel - A QRBarcodeSymbolModel enumeration member that specifies the symbol model and version of the QR barcode.

In addition to the members above, other QR write options not related to the barcode data can be set using the QRBarcodeWriteOptions class.

Use the static (or Shared in VB) BarcodeData.CreateDefaultBarcodeData method to create a new instance of QRBarcodeData that contains default parameters ready for writing to an image:

vb[VB Snippet] 
Dim qrData As QRBarcodeData = DirectCast(BarcodeData.CreateDefaultBarcodeData(BarcodeSymbology.QR), QRBarcodeData)

C# Snippet

QRBarcodeData qrData = BarcodeData.CreateDefaultBarcodeData(BarcodeSymbology.QR) as QRBarcodeData;

Example

This example writes a couple of QR barcodes with different options to an image and then reads them back.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Barcode; 
using Leadtools.ImageProcessing; 
 
 
public void QRBarcode_Example() 
{ 
   string imageFileName = Path.Combine(LEAD_VARS.ImagesDir, "MyQRBarcodes.tif"); 
 
   BarcodeEngine engine = new BarcodeEngine(); 
 
   // Create the image to write the barcodes to 
   int resolution = 300; 
   using (RasterImage image = RasterImage.Create((int)(8.5 * resolution), (int)(11.0 * resolution), 1, resolution, RasterColor.FromKnownColor(RasterKnownColor.White))) 
   { 
      // Write two QR barcodes 
      WriteBarcode(engine.Writer, image, QRBarcodeSymbolModel.Model1AutoSize, "QR Data 1", false); 
      WriteBarcode(engine.Writer, image, QRBarcodeSymbolModel.Model2Version30, "QR Data 2", true); 
 
      // Save the image 
      using (RasterCodecs codecs = new RasterCodecs()) 
      { 
         codecs.Save(image, imageFileName, RasterImageFormat.CcittGroup4, 1); 
      } 
   } 
 
   // Now read the barcodes again 
   using (RasterCodecs codecs = new RasterCodecs()) 
   { 
      using (RasterImage image = codecs.Load(imageFileName)) 
      { 
         // Read all the QR barcodes 
         ReadBarcodes(engine.Reader, image); 
      } 
   } 
} 
 
private void WriteBarcode(BarcodeWriter writer, RasterImage image, QRBarcodeSymbolModel symbolModel, string value, bool topLeft) 
{ 
   // Create the barcode data 
   QRBarcodeData barcode = BarcodeData.CreateDefaultBarcodeData(BarcodeSymbology.QR) as QRBarcodeData; 
   barcode.SymbolModel = symbolModel; 
   barcode.Value = value; 
   barcode.Symbology = BarcodeSymbology.QR; 
 
   // We will use the alignment to position the barcodes, so use all of the image 
   barcode.Bounds = new LeadRect(0, 0, image.ImageWidth, image.ImageHeight); 
 
   // Set the write options 
   QRBarcodeWriteOptions options = new QRBarcodeWriteOptions(); 
 
   if (topLeft) 
   { 
      options.HorizontalAlignment = BarcodeAlignment.Near; 
      options.VerticalAlignment = BarcodeAlignment.Near; 
   } 
   else 
   { 
      options.HorizontalAlignment = BarcodeAlignment.Far; 
      options.VerticalAlignment = BarcodeAlignment.Far; 
   } 
 
   options.GroupNumber = 0; 
   options.GroupTotal = 0; 
   options.XModule = 30; 
   options.ECCLevel = QRBarcodeECCLevel.LevelL; 
 
   // Write it 
   Console.WriteLine("Writing barcode with symbol model: {0} and Data: {1}", symbolModel, value); 
   writer.WriteBarcode(image, barcode, options); 
} 
 
private void ReadBarcodes(BarcodeReader reader, RasterImage image) 
{ 
   // Setup read options 
   QRBarcodeReadOptions options = new QRBarcodeReadOptions(); 
   options.EnableDoublePass = false; 
   options.EnableDoublePassIfSuccess = true; 
   options.EnablePreprocessing = true; 
 
   Console.WriteLine("Reading QR barcodes"); 
   BarcodeData[] barcodes = reader.ReadBarcodes(image, LeadRect.Empty, 0, new BarcodeSymbology[] { BarcodeSymbology.QR }, new BarcodeReadOptions[] { options }); 
   Console.WriteLine("{0} barcodes found:", barcodes.Length); 
   foreach (QRBarcodeData barcode in barcodes) 
   { 
      string value = BarcodeData.ParseECIData(barcode.GetData()); 
      if (string.IsNullOrEmpty(value)) 
         value = barcode.Value; 
 
      Console.WriteLine(" At {0}, symbol model: {1} data: {2} and symbology: {3}", barcode.Bounds, barcode.SymbolModel, value, barcode.Symbology); 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
}

Requirements

Target Platforms

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Help Version 22.0.2023.5.9

Leadtools.Barcode Assembly

Introduction

Getting Started

Namespaces

Leadtools.Barcode Namespace

Assemblies

QRBarcodeData Class

Reading Barcodes

Writing Barcodes

Reference