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Quick Question Regarding Conversions in Qt [SOLVED]

  • Bare in mind, I am sort of a newbie to C++ and Qt, So here is what I am trying to do. I cant seem to figure out the proper way to do this though. I am currently reading a udp socket into a char array "char updDataIn[103]"

    For certain purpose's, this absolutely needs to be a char. I have other code already functioning and working with the use of this variable. What I am trying to do here is convert the char into a long. Since it is a single char, some confusing has arose (not as easy as using atol()). I know I can use the toChar for Qt variables like QString so my thoughts were to do QChar of the char, and then make that a QString, and toLong on the postfix. Each previous calculation needs to be added to the current calculation since I am building a serial number string so output to a text box. Unfortunately, this doesn't seem to work, I was curious if anyone else had any other ideas on how to do this. I failed to find any easy ways with generic C++ to do this as well.

    Heres the code snipet:
    // *** build hardware serial number string ***
    serialNumber = QString(QChar(udpDataIn[61])).toLong(); // 1st part
    serialNumber = serialNumber + QString(QChar(udpDataIn[62]) << 8).toLong(); // 2nd part
    serialNumber = serialNumber + QString(QChar(udpDataIn[63]) << 16).toLong(); // 3rd part
    serialNumber = serialNumber + QString(QChar(udpDataIn[64]) << 24).toLong(); // 4th part
    ui->txtserialnumber->setText(QString(serialNumber)); // output to UI

    I get multiple errors when doing this due to it not liking the bit shifting process. Note: serialNumber is denoted as a Long.

    Edit: I fixed my issues, I added .toLong(); I still would like to know if their is an easier way to do this other than casting a million times. Thanks in advance!

  • Are you sure you have the bitshifts in the correct place in the code above? Looks as if you are trying to bitshift a QChar. You could use the QChar::digitValue() function to save yourself the hassle of going via QString since you are converting and shifting one digit at a time to build your id.

  • can you please show an example string that you get (in udpDataIn[61 - 64]) and show the expected result? It seems very difficult what you do there should be easier...

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