Serialize QPixmap in console app

[Misty River]

Hello,

I am trying to serialize a QPixmap between a server and a client app. The server is a console app and the client a gui one. The server always crash when I serialize the pixmap while the client stay alive.. so I'm guessing it has something to do with being a console app.. do I need to enable something in the project file ? I have already added += gui to use QPixmap ...

[VRonin]

Can you show us your code?

[Misty River]

@VRonin I'm afraid it is way way way to big to post

[VRonin]

Just the part where you serialise

[Misty River]

@VRonin

void Server::sendProfilePicture(QPixmap pProfilePicture, const QString & pPseudo)
{
    QByteArray paquet;
    QDataStream out(&paquet, QIODevice::WriteOnly);
    out << (quint64) 0;

    Message message(PROFILEPICTURE);
    message.setOption(0);
    message.setProfilePicture(pProfilePicture);

    out << message;
    out.device()->seek(0);
    out << (quint64) (paquet.size() - sizeof(quint64));
    if (socketFromPseudo(pPseudo) != NULL) {
        socketFromPseudo(pPseudo)->write(paquet);
    }
}

This will probably be Chinese without the rest of the code but this is where the crash happens...

[raven-worx]

@Misty-River
you need to create a QGuiApplication (instead of a QCoreApplication) in your server application.

[Hamed.Masafi]

QPixmap need to create in gui thread. I have had same problem with chat server application. You need to use QImage.
From qdoc:

Qt provides four classes for handling image data: QImage, QPixmap, QBitmap and QPicture. QImage is designed and optimized for I/O, and for direct pixel access and manipulation, while QPixmap is designed and optimized for showing images on screen. QBitmap is only a convenience class that inherits QPixmap, ensuring a depth of 1. Finally, the QPicture class is a paint device that records and replays QPainter commands.

So using QImage in server app is better than QPixmap.

[Misty River]

@Hamed.Masafi Ok thank you. I have switched to QImage and it stopped crashing.