QT 5.8 Removing margins from QGroupBox not working

Question

So i have a QGroupBox with a vertical layout inside of it.
There is a QWidget container at top(blue).

I have used setContentsMargins(0,0,0,0) for both the QGroupBox and the QWidget container yet no matter what i do i cannot get the QWidget container to be at (0,0) in the top left of the groupbox. Ive marked in red the spacing i want to remove.

Answer 1

Those are QLayout margins. Set them to zero.

Answer 2

You must algo set the margins of the layout to 0. Given a widget -- either your QGroupBox or your QWidget -- you can use the layout() method to access its underlying layout, and then set the margins on it. Something like this:

widget->layout()->setContentsMargins(0, 0, 0, 0);