QDialog exec() and getting result value

Some points :

1. Rather than using setResult() yourself, use QDialog::accept() and QDialog::reject().
2. It seems you are not taking full advantage of the signals and slots. You need the object which create the dialog (or another one) to listen to the signals of the dialog.
3. In your code you are not connecting signals to slots either.
4. With my fix onOKButtonClicked and onCancelButtonClicked are unnecessary.
5. With my fix you don't need showYourself(). Just call exec and with the events information will flow.

You need to add this code before showing the dialog (this assume it is in a dialog method):

QObject::connect(acceptButton, SIGNAL(clicked()), this, SLOT(accept()));
QObject::connect(rejectButton, SIGNAL(clicked()), this, SLOT(reject()));

In the caller object you have

void someInitFunctionOrConstructor(){
   QObject::connect(mydialog, SIGNAL(finished (int)), this, SLOT(dialogIsFinished(int)));
}

void dialogIsFinished(int){ //this is a slot
   if(result == QDialog::Accepted){
       //do something
       return
   }
   //do another thing
}

Another solution:

    // set signal and slot for "Buttons"
    connect(YesButton, SIGNAL(clicked()), dlg, SLOT(accept()));
    connect(NoButton, SIGNAL(clicked()), dlg, SLOT(reject()));

    // show modal window event loop and wait for button clicks
    int dialogCode = dlg->exec();

    // act on dialog return code
    if(dialogCode == QDialog::Accepted) { // YesButton clicked }
    if(dialogCode == QDialog::Rejected) { // NoButton clicked }