How to resize pages automatically in a QStackedWidgetContainer?

Hello,
In my project, I created a main window and its central widget is a QStackedWidget object. I added three pages to the stacked widget and none of them getting re-sized automatically when the main form is re-sized. How do i re-size all the pages if the size of the stacked widget changes.

You probably didn't layout content of the pages (each page!) itself, that's why QStackWidget resize but not the content.