1  MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
2  {
3    ui->setupUi(this);
4    QWidget *w = new QWidget();
5    QPushButton *btn1 = new QPushButton("One");
6    QPushButton *btn2 = new QPushButton("Two");
7    QPushButton *btn3 = new QPushButton("Three");
8    QPushButton *btn4 = new QPushButton("Four");
9    QPushButton *btn5 = new QPushButton("Five");
10   QGridLayout *gl = new QGridLayout();
11   gl->addWidget(btn1, 0, 0);
12   gl->addWidget(btn2, 0, 1);
13   gl->addWidget(btn3, 1,0,1,2);
14   gl->addWidget(btn4, 2, 0);
15   gl->addWidget(btn5, 2, 1);
16   w->setLayout(gl);
17   w->show();
18 }