Qt QObject::connect --> No such slot

Qt connect no such slot when slot definitely does exist qobject__connect_ no such slot QObject :: connect (button, SIGNAL (clicked ()), label, SLOT (setText )); Here we have tried a signal-slot link The aim of slot 18 QObject::connect: No such slot MainWindow::addItemToList in-- 이런 에러가 난다면, 아마도 시그널의 인자와 슬롯의 인자가 맞지 않아

cluedo slot QObject::connect: No such slot FenCalculatrice::FenCalculatrice::calculerOperation() in Designer_training: 10 QObject