#include <qapplication.h>#include <qwidget.h>#include <qprogressdialog.h>class MyMainWindow:public QWidget{ public:    MyMainWindow(); private:    QProgressDialog *pdialog;};MyMainWindow::MyMainWindow(){ setGeometry(100,100,200,50); pdialog = new QProgressDialog("Doing something ...","Abort Operation",100,this,"pdialog",TRUE); pdialog->show();  int x = 0; int i = 0; while (x <= 100) {   for (i=0;i<1000000;i++)   pdialog->setProgress(x);   x++; } }main(int argc,char **argv){ QApplication a(argc,argv); MyMainWindow w; a.setMainWidget(&w); w.show(); a.exec();}