So, you get an option to reload the QR code. While you can choose not to scan it, the QR code expires in the WhatsApp app after a while. When you open WhatsApp for the first time on Windows or Mac, the app straightway asks you to scan the QR code.

Here’s how to fix WhatsApp desktop QR code not loading problem.

Use the setQRData() call to change this.At times, the QR code won’t load or work to establish a successful connection with the phone. The interesting bits are in the overridden paintEvent() method.ĭata('Hello QR')//Note: The encoding fails with empty string so I just default to something else. Instead of listing a bunch of assumptions I will instead included my complete working minimalistic QRWidget implementation here. This might be bugs in the ancient version of the library that I am using You have been warned.įinally, before cleaning up, you need to convert the output to bitmap so that it can be rendered on the screen. For example passing 0 as version or using QR_MODE_AN failed with 'Invalid parameters'. Some combinations of parameters failed for no good reason. NOTE: After experimenting with the parameters I have passed to this function, I have learned that one needs to be careful. That is one line of code: QRcode *qr=QRcode_encodeString('my string', 1, QR_ECLEVEL_L, QR_MODE_8,0)

Next one must write the code that actually uses the library to encode some input string to QR format. This should be similar for most versions of Qt that I know. In my Qt5.2.0 project file (myproject.pro or similar) that meant appending the following line: LIBS += -lqrencode Next, you will have to add the library to your project. Simply download the tarball and follow the instructions from the source code download.

On other platforms you may have to build it from source by yourself. On my Ubuntu 13.10 that meant typing the following in a shell: sudo aptitude install libqrencode-dev There is a small QR-code generator library in pure C and without dependencies, called libqrencode.īefore you can use it, you will have to install it. UPDATE 3/3-2016: It has come to my attention that there is a small library project that does what my answer does but in a more 'prepackaged' way.

Qr code for link to windows