convert QPixmap to std::vector<unsigned char>

[saman_artorious]

I get the following when I grab a screen shot:

QPixmap originalPixmap = QPixmap::grabWidget(this);

QPixmap originalPixmap = QPixmap::grabWidget(this);

To copy to clipboard, switch view to plain text mode 

I need to convert originalPixmap to std::vector<unsigned char>.
The problem I face is when I convert this grabbed pixmap to qbytearray or qbuffer it's value becomes NULL! as an example:

QVariant myPixmap(QPixmap(QPixmap::grabWidget(this)));
 
    QByteArray myByteArray = myPixmap.toByteArray() ;
 
    qDebug() << myByteArray.size();  // 0 size

QVariant myPixmap(QPixmap(QPixmap::grabWidget(this)));

    QByteArray myByteArray = myPixmap.toByteArray() ;

    qDebug() << myByteArray.size();  // 0 size

To copy to clipboard, switch view to plain text mode 

or

QPixmap originalPixmap = QPixmap::grabWidget(this);
 
    QImage *image = new QImage(originalPixmap.toImage());
 
    QByteArray Array;
 
    QBuffer buffer(&Array);
 
    buffer.open(QIODevice::WriteOnly);
 
    image->save(&buffer);

QPixmap originalPixmap = QPixmap::grabWidget(this);

    QImage *image = new QImage(originalPixmap.toImage());

    QByteArray Array;

    QBuffer buffer(&Array);

    buffer.open(QIODevice::WriteOnly);

    image->save(&buffer);

To copy to clipboard, switch view to plain text mode 

again returns null string. am I missing something in the code?