How to transfer QString to QByteArray?

[victor wang]

Hi All:
I'm using qt5.5 on my computer and Linux+QT for my OS system.
I wanna compare the Array that I get from my MCU via RS23 with my QString.
Here is my program.

 bytesWritten = comport.write(BIOS_name,sizeof(BIOS_name));

    if (bytesWritten == -1)
    {
        qDebug("Failed to write the data to port");
    }
    else if (!comport.waitForBytesWritten(80))
    {
        qDebug("Operation timed out or an error occurred for port");
    }
    readData=comport.readAll();
    while(comport.waitForReadyRead(80))
        readData.append(comport.readAll());
    ui->textEditPT_Ignitionversionshow->append(readData.constData());
    if (comport.error() == QSerialPort::ReadError)
    {
        ui->lineEditPT_IgnitionResult->setText("Failed");
        ui->pushButtonPT_Ignition_ResultLight->setStyleSheet("QPushButton{background-color:red;}");
        test_result[7]=false;

    }
    else if (comport.error() == QSerialPort::TimeoutError && readData.isEmpty())
    {
        ui->lineEditPT_IgnitionResult->setText("Failed");
        ui->pushButtonPT_Ignition_ResultLight->setStyleSheet("QPushButton{background-color:red;}");
        test_result[7]=false;
    }
    //else if(readData.contains("FA3A120-000000000-000-AG121-WN"))
    else if(readData.contains(ignition_firmware))
    {
        if(!ignition_bios_name_error)
        {
            ui->textEditPT_Ignitionversionshow->append(readData.constData());
            ui->lineEditPT_IgnitionResult->setText("Pass");
            ui->pushButtonPT_Ignition_ResultLight->setStyleSheet("QPushButton{background-color:green;}");
            test_result[7]=true;
        }
        else
        {
            ui->textEditPT_Ignitionversionshow->append("BIOS_name is wrong Please check the firmware of EC");
            ui->textEditPT_Ignitionversionshow->append(readData.constData());
            ui->lineEditPT_IgnitionResult->setText("Failed");
            ui->pushButtonPT_Ignition_ResultLight->setStyleSheet("QPushButton{background-color:red;}");
            test_result[7]=false;
        }
    }

But I will get the error like below.

mainwindow.cpp: In member function 'void MainWindow::on_pushButtonPT_Ignitionversion_clicked()':
     ^
mainwindow.cpp:2649:48: error: no matching function for call to 'QByteArray::contains(QString&)'
     else if(readData.contains(ignition_firmware))
                                                ^
In file included from ../../sysroots/cortexa9hf-vfp-neon-poky-linux-gnueabi/usr/include/qt5/QtCore/qstring.h:42:0,
                 from ../../sysroots/cortexa9hf-vfp-neon-poky-linux-gnueabi/usr/include/qt5/QtCore/qobject.h:41,
                 from ../../sysroots/cortexa9hf-vfp-neon-poky-linux-gnueabi/usr/include/qt5/QtWidgets/qwidget.h:38,
                 from ../../sysroots/cortexa9hf-vfp-neon-poky-linux-gnueabi/usr/include/qt5/QtWidgets/qmainwindow.h:37,
                 from ../../sysroots/cortexa9hf-vfp-neon-poky-linux-gnueabi/usr/include/qt5/QtWidgets/QMainWindow:1,
                 from mainwindow.h:4,
                 from mainwindow.cpp:1:
../../sysroots/cortexa9hf-vfp-neon-poky-linux-gnueabi/usr/include/qt5/QtCore/qbytearray.h:585:13: note: candidate: bool QByteArray::contains(char) const
 inline bool QByteArray::contains(char c) const
             ^
../../sysroots/cortexa9hf-vfp-neon-poky-linux-gnueabi/usr/include/qt5/QtCore/qbytearray.h:585:13: note:   no known conversion for argument 1 from 'QString' to 'char'
../../sysroots/cortexa9hf-vfp-neon-poky-linux-gnueabi/usr/include/qt5/QtCore/qbytearray.h:635:13: note: candidate: bool QByteArray::contains(const char*) const
 inline bool QByteArray::contains(const char *c) const
             ^
../../sysroots/cortexa9hf-vfp-neon-poky-linux-gnueabi/usr/include/qt5/QtCore/qbytearray.h:635:13: note:   no known conversion for argument 1 from 'QString' to 'const char*'
../../sysroots/cortexa9hf-vfp-neon-poky-linux-gnueabi/usr/include/qt5/QtCore/qbytearray.h:583:13: note: candidate: bool QByteArray::contains(const QByteArray&) const
 inline bool QByteArray::contains(const QByteArray &a) const

How can I compare QString and QBytearray?
Thanks in Advanced!

[SGaist]

Hi,

The most simple would be to make ignition_firmware a QByteArray also.

[Taz742]

@victor-wang
toUtf8() return a QByteArray.

For Example:

QString str("abcd");
QByteArray br = str.toUtf8();

[SGaist]

@Taz742 while technically correct, it's a bit overkill in this case.