#include <qapplication.h>#include <qwidget.h>#include <qpushbutton.h>#include <qfont.h>#include <qlayout.h>class MyMainWindow:public QWidget{ public:    MyMainWindow();};MyMainWindow::MyMainWindow(){ setMinimumSize(200,200); QPushButton *b1 = new QPushButton("Button1",this); b1->setMinimumSize(200,100); b1->setFont(QFont("Times",18,QFont::Bold));  QPushButton *b2 = new QPushButton("Button2",this); b2->setMinimumSize(200,100); b2->setFont(QFont("Times",18,QFont::Bold)); QVBoxLayout *vbox = new QVBoxLayout(this); vbox->addWidget(b1); vbox->addWidget(b2);}main(int argc,char **argv){ QApplication a(argc,argv); MyMainWindow w; w.setGeometry(100,100,200,200); a.setMainWidget(&w); w.show(); a.exec();}