QRBarcodeData Class

Summary

Contains the data for a single QR barcode.

Syntax

Objective-C

C++

Java

[SerializableAttribute()] 
public class QRBarcodeData : BarcodeData

<TypeConverterAttribute()> 
<SerializableAttribute()> 
Public Class QRBarcodeData  
   Inherits BarcodeData 
   Implements System.ICloneable

@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:

SymbolModel
An 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 - An 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 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.

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:\LEADTOOLS21\Resources\Images"; 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.Barcode 
Imports Leadtools.ImageProcessing 
 
Public Sub QRBarcode_Example() 
   Dim imageFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "MyQRBarcodes.tif") 
 
   Dim engine As New BarcodeEngine() 
 
   ' Create the image to write the barcodes to 
   Dim resolution As Integer = 300 
   Using image As RasterImage = RasterImage.Create(CType(8.5 * resolution, Integer), CType(11.0 * resolution, Integer), 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 codecs As New RasterCodecs() 
         codecs.Save(image, imageFileName, RasterImageFormat.CcittGroup4, 1) 
      End Using 
   End Using 
 
   ' Now read the barcodes again 
   Using codecs As New RasterCodecs() 
      Using image As RasterImage = codecs.Load(imageFileName) 
         ' Read all the QR barcodes 
         ReadBarcodes(engine.Reader, image) 
      End Using 
   End Using 
End Sub 
 
Private Sub WriteBarcode(ByVal writer As BarcodeWriter, ByVal image As RasterImage, ByVal symbolModel As QRBarcodeSymbolModel, ByVal value As String, ByVal topLeft As Boolean) 
   ' Create the barcode data 
   Dim barcode As QRBarcodeData = DirectCast(BarcodeData.CreateDefaultBarcodeData(BarcodeSymbology.QR), 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 
   Dim options As New QRBarcodeWriteOptions() 
 
   If topLeft Then 
      options.HorizontalAlignment = BarcodeAlignment.Near 
      options.VerticalAlignment = BarcodeAlignment.Near 
   Else 
      options.HorizontalAlignment = BarcodeAlignment.Far 
      options.VerticalAlignment = BarcodeAlignment.Far 
   End If 
 
   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) 
End Sub 
 
Private Sub ReadBarcodes(ByVal reader As BarcodeReader, ByVal image As RasterImage) 
   ' Setup read options 
   Dim options As New QRBarcodeReadOptions() 
   options.EnableDoublePass = False 
 
   Console.WriteLine("Reading QR barcodes") 
   Dim barcodes() As BarcodeData = reader.ReadBarcodes(image, LeadRect.Empty, 0, New BarcodeSymbology() {BarcodeSymbology.QR}, New BarcodeReadOptions() {options}) 
   Console.WriteLine("{0} barcodes found:", barcodes.Length) 
   For Each barcode As QRBarcodeData In barcodes 
      Dim value As String = BarcodeData.ParseECIData(barcode.GetData()) 
      If String.IsNullOrEmpty(value) Then 
         value = barcode.Value 
      End If 
 
      Console.WriteLine(" At {0}, symbol model: {1} and data: {2}", barcode.Bounds, barcode.SymbolModel, value) 
   Next 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\LEADTOOLS21\Resources\Images" 
End Class

Requirements

Target Platforms

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Help Version 21.0.2021.7.2

Leadtools.Barcode Assembly

Introduction

Getting Started

Namespaces

Leadtools.Barcode Namespace

Assemblies

QRBarcodeData Class

Reading Barcodes

Writing Barcodes

Reference