How to find Version of Qt?
qmake-qt5 –version or qmake –version
qt4
How to get sender widget with a signal/slot mechanism?
Use QObject::sender() in the slot, like in the following Example: void MainWindow::someSetupFunction( void ) { … connect( _foobarButton, SIGNAL(clicked()), this, SLOT(buttonPressedSlot()) ); } void MainWindow::buttonPressedSlot() { // e.g. check with member variable _foobarButton QObject* obj = sender(); if( obj == _foobarButton ) { … } // e.g. casting to the class you know its connected … Read more
How to make a Qt Widget grow with the window size?
In Designer, activate the centralWidget and assign a layout, e.g. horizontal or vertical layout. Then your QFormLayout will automatically resize. Always make sure, that all widgets have a layout! Otherwise, automatic resizing will break with that widget! See also Controls insist on being too large, and won’t resize, in QtDesigner
What’s the difference between QMainWindow, QWidget and QDialog?
A QWidget is the base class for all drawable classes in Qt. Any QWidget-based class can be shown as a window by showing it when it has no parent. A QDialog is based on QWidget, but designed to be shown as a window. It will always appear in a window, and has functions to make … Read more