Resize Policy not recognized

I have made a GUI to which I am adding widgets at run time. I click a button and a row gets added to a QFrame. Everything works fine until I add enough rows to reach the bottom of the GUI window. When this happens, I would like the window to automatically resize. I have tried setting the Vertical Size Policy to "Expanding" for everything - the GUI, the enclosing QFrame, and the row (another QFrame). I have also tried calling updateGeometry(), update(), and repaint(). Nothing seems to work. How can I make the GUI expand dynamically to fit all the contents? Thanks for your help!

Set the size constraint property of the layout to Minimum or to Fixed.