Qmainwindow QWidget size

[seltra]

How can i change the centralwidget's size without changing Mainwindow's size.
I want MainWindow width: 300 height: 300
centralWidget width: 500 hegiht: 500

When i change geometry property of centralwidget, mainwindow's property changes automatically?
Thank you

[tbscope]

You might want to set a scroll area as the central widget, then you can resize whatever content in the scroll area.