@Pl45m4 said in QTreeView child of QMainWindow not resizing with main window:
Remove the current layout and the ElementView. Drag a new ElementView straight on the centralWidget and then rightclick and "lay out".
I was doing this, but I misinterpreted what the rightclick applied to. I thought it applied to the new Element View I dragged onto the centralWidget, and its "Lay out" menu had most everything disabled. When I tried rightclicking on the centralWidget outside of the ElementView, its menu had the selections all available.
All is working now and I have removed my resizeEvent().
@Pl45m4 and @JonB - All comments are much appreciated!