For get key events in event filter, this function must be called in class overrided event filter function before:
this->installEventFilter(this);
You can get key press event like this example:
bool ExampleApplication::eventFilter(QObject *object, QEvent *ev) { if (ev->type() == QEvent::KeyPress) { QKeyEvent* keyEvent = (QKeyEvent*)ev; if (keyEvent->key() == Qt::Key_A) { lbl->setText("Key pressed : A"); } } return false; }