expanding widgets inside a Qtabwidget

Question

Why does the widgets inside a QTabWidget don't resize?

All my widgets resize except for the ones inside the tabs, even the tabs resize, but not the items inside it.

Is this because of the type of layout as I show in the figure?

I can's assign a layout to it. this is before and after maximizing the window.

Answer 1

Why can't you assign a layout to it? You just have to give each tab a layout. Drag your widget into the tab. Select the tab, not the widget, click on one of the layouts in the top row of the designer. Your widget will fill the whole tab and resize nicely.