Why I am unable to change the QR Code's size in iText7? - itext7

Question

How to change QR Code size?
using (iText.Kernel.Pdf.PdfReader _pdf_reader =
new iText.Kernel.Pdf.PdfReader("tmp/example.pdf"))
{
using (iText.Kernel.Pdf.PdfDocument pdfDoc = new iText.Kernel.Pdf.PdfDocument(_pdf_reader, new iText.Kernel.Pdf.PdfWriter("tmp/output.pdf").SetSmartMode(true)))
{
BarcodeQRCode qrc = new BarcodeQRCode("https://google.com");
PdfFormXObject xObject = qrc.CreateFormXObject(ColorConstants.BLACK, pdfDoc);
float _w = pdfDoc.GetPage(1).GetPageSize().GetWidth();
float _h = pdfDoc.GetPage(1).GetPageSize().GetHeight();
PdfCanvas canvas = new PdfCanvas(pdfDoc.GetPage(1));
canvas.SaveState();
canvas.SetFillColor(ColorConstants.LIGHT_GRAY);
//canvas.Rectangle(_w - 90, _h - 90, 100, 100);
canvas.Fill();
canvas.RestoreState();
canvas.AddXObject(xObject, _w - qrc.GetBarcodeSize().GetWidth(), _h - qrc.GetBarcodeSize().GetHeight());
}
}
I try:
qrc.GetBarcodeSize().GetHeight();
qrc.GetBarcodeSize().GetWidth();
it returns 33
I try to set Height & Width to 100 like below:
qrc.GetBarcodeSize().SetHeight(100);
qrc.GetBarcodeSize().SetWidth(100);
and then check the size again, but it keeps returning 33, is it a bug? or Did I miss something?
please help
thanks
Don

Answer 1

I try to set Height & Width to 100 like below:
Actually, you can`t change the QrCode side this way.
In fact, QRcode is an n*n grid where n depends on some parameters as a QR code version and the error correction level.
When generating, iText uses the smallest version that can fit the content. This is version 4 (33*33) in your case.
The easiest way to change the size of QrCode in a document is by using the version of the createFormXObject method which accepts the moduleSide parameter.
float moduleSize = 100/qrc.GetBarcodeSize().GetHeight();
qrc.createFormXObject(foreground, moduleSize, document)
Module size here is size of the barcode`s grid cell (1 by default).

Answer 2

iTxt 7 Qrcode size effected by three parameter in hints, example example for your reference.
//C# code
//Prepare all necessary properties to create the qrcode
IDictionary<EncodeHintType, Object> hints = new Dictionary<EncodeHintType, object>();
//default character set (ISO-8859-1)
hints[EncodeHintType.CHARACTER_SET] = "UTF-8";
//Qrcode Error correction level L,M,Q,H
//default ErrorCorrectionLevel.L
hints[EncodeHintType.ERROR_CORRECTION] = ErrorCorrectionLevel.L;
//Qrcode minimal version level
//default 4
hints[EncodeHintType.MIN_VERSION_NR] = 6;
string code = "Qrcode content here";
BarcodeQRCode qrcode = new BarcodeQRCode(code, hints);