Q:

Deactivate QSpinBox if a certain value from QComboBox is selected

Is it possible to deactivate a QSpinBox if a certain value is chosen in a QComboBox.  I've tried several things, but either the QSpinbox is deactived all the time or it wont deactivate at all.  

A:

If I understand the question correctly, something along these lines should work:
connect( myComboBox, SIGNAL(currentIndexChanged(int)), this, SLOT(comboBoxIndexChanged()) );

...

void comboBoxIndexChanged() {
    if( comboBox->currentText() == MagicalValue )
        mySpinBox->setEnabled( false );
    else
        mySpinbox->setEnabled( true );
}

