Access MainWindow from different class

[peili]

I do have the following classes:
@#include <QApplication>
#include <QComboBox>
#include "mainwindow.h"
MainWindow *w;
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();

return a.exec();

}
@

and

@#include "mainwindow.h"

MainWindow::MainWindow()
{
wtr = new WindowTitleReader();
this->setWindowTitle("Selected Window Title Demo");
}

MainWindow::~MainWindow()
{

}@

In WindowTitleReader i would like to add a QComboBox to MainWindow.
I tried this Code:
@ MainWindow * win = (MainWindow *) QApplication::activeWindow();
QComboBox * combo = new QComboBox(win);@

But it doesn't add my QComboBox to MainWindow.

Any idea?

[SGaist]

Hi,

You are taking the wrong approach, please have a look at the examples and demos that comes with Qt. They'll show in details how to build a GUI