Generating QR codes and decoding them are not supported by .NET natively, so we have to use some 3rd party library.
I chose a very simple-to-use one from NuGet: MessagingToolkit.QRCode
I’ve created a new WinForms application, added this package to the project with this form:
Only those 2 buttons have event subscription: to Click event:
Now, that’s all. Type any text into the first textbox, click on Encode, save the QR Code as a jpg file, then click on decode button, browse for this QR Code jpg file and you’ll see it decoded.