QComboBox::itemData() problem

[MarkoSan]

Hi to all!

I've created combo box on some widget with:

m_pDatabaseSelector=new QComboBox(this);    // creates new combo box
    Q_CHECK_PTR(m_pDatabaseSelector);    // checks creation

m_pDatabaseSelector=new QComboBox(this);    // creates new combo box
    Q_CHECK_PTR(m_pDatabaseSelector);    // checks creation

To copy to clipboard, switch view to plain text mode 

and then fill it with:

m_pDatabaseSelector->addItem(strdbType);    // adds db type to combo box
    m_pDatabaseSelector->addItem("ODBC");    // adds db type to combo box
    m_pDatabaseSelector->addItem("SQLite");    // adds db type to combo box

m_pDatabaseSelector->addItem(strdbType);    // adds db type to combo box
    m_pDatabaseSelector->addItem("ODBC");    // adds db type to combo box
    m_pDatabaseSelector->addItem("SQLite");    // adds db type to combo box

To copy to clipboard, switch view to plain text mode 

Combo box is shown and all item are in it as should be. Now, I've connected data selection signal with my slot:

connect(m_pDatabaseSelector,
            SIGNAL(currentIndexChanged(int)),
            this,
            SLOT(itemChanged(int)));    // signal connector

connect(m_pDatabaseSelector,
            SIGNAL(currentIndexChanged(int)),
            this,
            SLOT(itemChanged(int)));    // signal connector

To copy to clipboard, switch view to plain text mode 

and here the code for itemChanged(int):

void CDatabaseSettingsPage::itemChanged(int iSelectedIndex)
{
    qDebug() << "iSelectedIndex:" << iSelectedIndex;
    qDebug() << "m_pDatabaseSelector->itemData(iSelectedIndex).toString():" << m_pDatabaseSelector->itemData(iSelectedIndex).toString();
    m_pAppSettings->updateRecord(databaseSettingKey,
                                 strDatabaseTypeKey,
                                 m_pDatabaseSelector->itemData(iSelectedIndex).toString());
}

void CDatabaseSettingsPage::itemChanged(int iSelectedIndex)
{
    qDebug() << "iSelectedIndex:" << iSelectedIndex;
    qDebug() << "m_pDatabaseSelector->itemData(iSelectedIndex).toString():" << m_pDatabaseSelector->itemData(iSelectedIndex).toString();
    m_pAppSettings->updateRecord(databaseSettingKey,
                                 strDatabaseTypeKey,
                                 m_pDatabaseSelector->itemData(iSelectedIndex).toString());
}

To copy to clipboard, switch view to plain text mode 

Well, itemData() returns empty string, iSelectedIndex is correclty setup. Why??

[jpn]

QComboBox::itemData() returns the optional user data that can be associated to each item. I guess you're interested in QComboBox::itemText().

[MarkoSan]

QComboBox::itemData() returns the optional user data that can be associated to each item. I guess you're interested in QComboBox::itemText().

Thanks, but just one more question: Why is then itemData() used in examples instead of itemText(), in examples there is also text retreived?

[caduel]

itemData is internal, whereas itemText is user-visible.
If you should ever need to translate your app, then you probably do not want your internals affected. Therefore it is often a good idea to be 'independent' of what (and how) some data is presented to the user.

Moreover, you can store other (additional, different, more) stuff in itemData. E.g. you might show some text but need some internal numeric ID, which you may put in itemData.

HTH

[MarkoSan]

Sorry, I had a dumb question, I deleted it, thanks for answers, problem has been solved.