I want to create a simple example for using a QOpenGLContext in QT5.
I have found "this":http://www.youtube.com/watch?v=VxsS7u-vgc8 YouTube example and followed the steps exactly.
One cannot see everything especially not the main function.

I have written a simple class deriving from QWindow (as you can see in the video).

@
//header file
class Window: public QWindow
{
private:
QOpenGLContext *_glContext;
public:
Window(QScreen *screen=0);
}@

@
//.cpp file

Window::Window(QScreen *screen): QWindow(screen)
{
setSurfaceType(OpenGLSurface);

QSurfaceFormat fmt;
fmt.setMajorVersion(4);
fmt.setMinorVersion(2);
fmt.setProfile(QSurfaceFormat::CoreProfile); //whatever this is

this->setFormat(fmt);

create();

resize(300, 300);

_glContext = new QOpenGLContext();
_glContext->setFormat(fmt);

_glContext->create();

if(!_glContext->isValid())
qCritical()<<"The OpenGL context is invalid!"; //I allways get this message

//now another test:
//the next line prints: "Window format version is: 4.2" which is correct
qDebug()<<"Window format version is: "<<this->format().majorVersion()<<"."<<this->format().minorVersion();
//the next line prints: "Context format version is: 2.0" Which is ofcourse not correct! WTF?
qDebug()<<"Context format version is: "<<_glContext->format().majorVersion()<<"."<<_glContext->format().minorVersion();
}
@

As you can see, the format of the Window does not match the format of the context!!??!??
Is this a bug or am i missing something?? Maybe i do it wrong in the main, already?

@
#include "window.h"
int main(int argc, char *argv[])
{
QApplication a(argc, argv);

a.setApplicationName("test");
a.setApplicationVersion("0.1");

Window w; //do i have to create a QScreen first to give it to the Window?
w.show(); //A white window of size 300x300 appears
}@

I need to have a OpenGL 4.2 context!

Any help would be nice!