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How can I connect a QPushButton and a QComboBox?

I created a SLOT that accepts 2 parameters, a pointer to the QComboBox and the index of the selected item:

void modificaExp::eliminaExp(QComboBox *combo,int value)
{
   ......
    combo->removeItem(value);
   ....
}

the widgest are there:

QComboBox* combo=new QComboBox();
combo->addItem("ciao1");
combo->addItem("ciao44");
combo->addItem("ciao222");
combo->addItem("ciao555");

QPushButton* delButton=new QPushButton();
delButton->setText("delete");

   connect(delButton, SIGNAL(clicked()), this, SLOT( eliminaExp(combo,combo->currentIndex() )));

so, when I click on delButton the element stays there. I think there is a problem in the connect command, specifically I think than the slot is not called.

m.s.
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ale666
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  • `connect` does not work this way. If you're using Qt4, you'll have to pass `combobox` to a slot somehow (make it a class member, or via `setProperty`). If you're using Qt5, you can switch to a 'new' version of `connect` and write a lambda. – Amartel Jul 23 '15 at 11:58
  • thanks, you're right!! you save my project :D – ale666 Jul 23 '15 at 12:05

2 Answers2

1

Are you sure you need this slot with two parameter?

Another simple way:

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent)
{
    setupUi(this);

    connect(deleteButton, SIGNAL(clicked(bool)), this, SLOT(deleteSlot()));

}

void MainWindow::deleteSlot()
{
    comboBox->removeItem(comboBox->currentIndex());
}
t3ft3l--i
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0

  1. The slot should have the same type and equal or less number of arguments than the signal

  2. Declare the QComboBox and the QPushButton objects in the header modificaexp.h 

     private:
 QComboBox* combo;
 QPushButton* delButton;

  3. modificaexp.cpp

    combo=new QComboBox();
combo->addItem("ciao1");
combo->addItem("ciao44");
combo->addItem("ciao222");
combo->addItem("ciao555");

delButton=new QPushButton();
delButton->setText("delete");

connect(delButton, SIGNAL(clicked()), this, SLOT( eliminaExp()));

  4. Modify the slot 

     void modificaExp::eliminaExp()
 {           
    combo->removeItem(combo->currentIndex());        
 }

  5. Refer the Qt signal slot documentation

techneaz
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