[Qt-interest] Convert from a QPixmap into a QByteArray, and back

[Scott Aron Bloom]

This this…..

 

Scott

 

int main( int argc, char ** argv )

{

      QApplication appl( argc, argv );

 

      QPixmap screen = QPixmap::grabWindow( QApplication::desktop()->winId(), 0, 0, 500, 500 );

 

      QLabel label;

      label.setPixmap( screen );

      label.show();

 

      screen.save( "7777.png" );

 

      QPixmap screenLoaded( "7777.png" );

      QLabel label2;

      label2.setPixmap( screenLoaded );

      label2.show();

 

      QByteArray bytes;

      QDataStream out( &bytes, QIODevice::WriteOnly );

      out << screen;

 

      QDataStream in( &bytes, QIODevice::ReadOnly );

      QPixmap screenStream;

      in >> screenStream;

      QLabel label3;

      label3.setPixmap( screenStream );

      label3.show();

 

      return appl.exec();

}

 

Works for me…


Scott

 

 

From: qt-interest-bounces at trolltech.com [mailto:qt-interest-bounces at trolltech.com] On Behalf Of Gabriele Kahlout
Sent: Tuesday, May 18, 2010 2:54 PM
To: qt-interest at trolltech.com
Subject: [Qt-interest] Convert from a QPixmap into a QByteArray, and back

 

Hello,

In the process of debugging I've found myself unable to assert the following code:

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    const QPixmap screen = QPixmap::grabWindow(QApplication::desktop()->winId());
    QByteArray *bytes = new QByteArray();
    QDataStream out(bytes, QIODevice::WriteOnly);
    out << screen;
    QPixmap* screen1 = new QPixmap();
    screen1->loadFromData(bytes->data());
    std::cout << screen1->save("7777.png", "PNG") << endl;
    std::cout << screen.save("6666.png", "PNG") << endl;
    return a.exec();
}


All I'm doing is trying to convert from a QPixmap into a QByteArray, and back. Although the code is mostly verbatim from QPixmap and QDataStream, it doens't work. Indeed screen1 fails to save into 7777.png.

Your help, fixing this code, is greatly appreciated.

-- 
Regards, 
K. Gabriele

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