How to make a QPushButton disabled

I created lots of QPushButtons, added clicked signal and a slot name deneme() to all of the buttons with QT DESIGNER and the thing I want to do is; when I clicked any button, some operation should be done and lastly the button should be disabled but we do not know which button is clicked. I know I can disable the buttons with setEnabled() and isEnabled() but I do not know how to disable them.

If I understood correctly you connected various QPushButtons to the same slot. Inside of the slot deneme() you want to know which of the buttons was clicked. You can do something like:

  void deneme() {
    QPushButton * b = qobject_cast<QPushButton *>(sender());
    if (b) {
       if (b == button1) { //button1 clicked
           //doSomething();
       } 
       else {
          if (b == button2) {
             //doSomething();
          }
       }
       b->setEnabled(false);
    }
  }