aarelovich aarelovich - 1 month ago 8x
C++ Question

Is it possible to remove borders a single QWidget around a QMainWindow?

This is a very simple problem to reproduce. Create a new project with Qt Creator with a

. Using designer add a single widget (it doesn't matter which one) and then use the right button to set a layout (any layout as with a single widget the results are always the same).

There will be a gray border around the widget. I would like to remove this border so that the widget occupies the entirety of the main window area (which Qt always names
). Basically the single widget is all I want to see.

Is this possible? If so, how?


Yes, it's possible. All you need is setting margins of that centralWidget to 0. (note that you should first set up a layout)

In properties panel set the following properties to 0.

  • layoutLeftMargin
  • layoutTopMargin
  • layoutRightMargin
  • layoutBottomMargin

enter image description here

Also note that using a QWidget (not QMainWindow) as your main app window is perfectly valid, so if your app has only one widget, you won't need a QMainWindow at all. It's enough to show that widget.