I have used ZXing barcode library in android project and everything is working fine for me
IntentIntegrator integrator = new IntentIntegrator(UserRegistered.this);
integrator.initiateScan(IntentIntegrator.ALL_CODE_TYPES);
And on activity result I have handled all my logic
This barcode scanner shows string values on screen but I want to put some secret inside the QR code and want return SCAN_RESULT value but not want to show it on screen.
How can I hide my secret data from end user while available to me as a SCAN_RESULT?
Hm, you could encode non-printable whitespace characters in the QR code, and somehow invent an encoding scheme using those types of chars that encodes something else. It would still be in plain sight in the data, but would not print because the extra chars are unprintable.
It's not a great solution, and isn't secure, but might be suitable for your use case.