console message

[mickey]

Hi, after nmake (without warning or erros), I launched my app and immediately appear
a console message:


QPaintDevice: Must construct a QApplication before a QPaintDevice

And app doesn't start. I never see it first.....what happen? thanks...

[gfunk]

Did you make a QApplication object?
What's your main() function look like?

[mickey]

my app was working first.......


#include <qapplication.h>
#include <qsplashscreen.h>
#include "mymainform.h"
int main( int argc, char ** argv )
{
QApplication a( argc, argv );

if (!QGLFormat::hasOpenGL())
qFatal("This system has no OpenGL support");

QSplashScreen splash(QPixmap::fromMimeSource("splash.jpg"));
splash.show();
splash.message("Loading ... please wait", 0, QColor(255,255,255) );
a.processEvents();

myMainForm W;
//W.resize(600,500);
a.setMainWidget(&W);

W.show();
a.connect( &a, SIGNAL( lastWindowClosed() ), &a, SLOT( quit() ) );
splash.finish(&W);
return a.exec();
}

[wysota]

Do you have any global variables which might be using a paint device? Global vars are created before main() is called (thus before QApplication object is created).

[mickey]

I think it was this below, a variabile of mainform class but initialized as global....
is there a way to do this below without that error? (I'd like prog variabile global; thanks


//mainform.ui.h
myProgressDialog* prog = new myProgressDialog("Saving file...", "Cancel", 0, 1);
void MainForm::init()
{
........
}

[wysota]

Initialise it after QApplication is created, for example in main().

[jacek]

is there a way to do this below without that error?
Yes, just initialize it to 0 here and create myProgressDialog after you instantiate QApplication.


I'd like prog variabile global;
Global variables are dangerous.