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QRBarcodeData Class

Summary
Contains the data for a single QR barcode.
Syntax
C#
Objective-C
C++
Java
[SerializableAttribute()] 
public class QRBarcodeData : BarcodeData 
@interface LTQRBarcodeData : LTBarcodeData<NSCopying> 
public class QRBarcodeData extends BarcodeData 
[TypeConverterAttribute()] 
[SerializableAttribute()] 
public ref class QRBarcodeData : public BarcodeData, System.ICloneable   
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:

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:

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 barcode with different options to an image and then reads them back.

C#
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; 
 
	// 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; 
 
	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} and data: {2}", barcode.Bounds, barcode.SymbolModel, value); 
	} 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
} 
Requirements

Target Platforms

Help Version 22.0.2022.4.4
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Leadtools.Barcode Assembly

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© 1991-2022 LEAD Technologies, Inc. All Rights Reserved.