Do you have to use Layout management to show the QwizardPage contents?

[litroncn]

I create a page named TestPage, this is its constructor:

TestPage::TestPage(QWidget *parent)
     :QWizardPage(parent)
{
     QPushButton *button = new QPushButton("Start");
     QVBoxLayout *layout = new QVBoxLayout; 
 
     layout->addWidget(button); 
     setLayout(layout);
}

TestPage::TestPage(QWidget *parent)
     :QWizardPage(parent)
{
     QPushButton *button = new QPushButton("Start");
     QVBoxLayout *layout = new QVBoxLayout; 

     layout->addWidget(button); 
     setLayout(layout);
}

To copy to clipboard, switch view to plain text mode 

When I run it, the button appears on the page. However, if I do the following…

TestPage::TestPage(QWidget *parent)
     :QWizardPage(parent)
{
     QPushButton *button = new QPushButton(this);
}

TestPage::TestPage(QWidget *parent)
     :QWizardPage(parent)
{
     QPushButton *button = new QPushButton(this);
}

To copy to clipboard, switch view to plain text mode 

…the button is invisible. So, to show the page contents do I need to use layout management? Or is there another way to implement displaying a button or other widgets without using layout management ?

Thanks in advance