How can I get the selected VALUE out of a QCombobox?

Question

In Qt, I can get the selected text of a QComboBox by using the combobox->currentText() method. How can I get the selected value?

I searched for help but I couldn't find a method currentData() which I expected to find. I could only find combobox->currentIndex()

Is there a smarter way to do it other than combobox->itemData(combobox->currentIndex())?

Update: This is no longer necessary as of Qt 5. A currentData() method has been added http://doc.qt.io/qt-5/qcombobox.html#currentData-prop

score 103 · Accepted Answer · answered Jan 13 '10 at 16:01

103

It seems you need to do combobox->itemData(combobox->currentIndex()) if you want to get the current data of the QComboBox.

If you are using your own class derived from QComboBox, you can add a currentData() function.

answered Jan 13 '10 at 16:01

Patrice Bernassola

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Thanks. I just used this tip in my program. – Brian Stinar Oct 08 '10 at 20:06
1

@Patrice Bernassola However the switch operation of type 'QVariant' :`combobox->itemData(combobox->currentIndex())` is illegal !!! Why ? – The Beast Jan 23 '16 at 01:49
This doesn't work if nothing is selected i.e. `currentIndex = -1`. It will either return the data from the last index or raise an error if the QComboBox is empty. – johnson Jan 09 '18 at 15:10

score 28 · Answer 2 · answered Jan 21 '13 at 07:58

28

This one can get the text of current index:

QString cb = cbChoice ->currentText();

answered Jan 21 '13 at 07:58

littlecodefarmer758

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How does this help? `currentText` is what the OP is aware of already... – Aconcagua Jan 31 '18 at 09:55

ufukgun · Answer 3 · 2010-01-13T13:45:08.243

you can set QVariant data for all items, then you can get the value when you need it.

there is an example code for this situation:

ui.comboBoxSheetSize->addItem("128 m", QVariant(128));
ui.comboBoxSheetSize->addItem("256 m", QVariant(256));
ui.comboBoxSheetSize->addItem("512 m", QVariant(512));
ui.comboBoxSheetSize->addItem("1024 m", QVariant(1024));

...

void Page::onComboSheetSizeChanged( int index )
{
 int value = ui.comboBoxSheetSize->itemData(index).toInt();
}

by the way, i think i misunderstood your question. i think the way you get data is smart enough?

score 11 · Answer 4 · answered Jun 16 '14 at 12:46

11

The member function QComboBox::currentData has been added since this question was asked, see this commit

answered Jun 16 '14 at 12:46

joaerl

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For documentation see: http://doc.qt.io/qt-5/qcombobox.html#currentData-prop. The property is available since Qt 5.2. – m4tx Jan 03 '16 at 17:17

score 8 · Answer 5 · answered Dec 02 '14 at 09:09

8

I had same issue

I have solved by

value = self.comboBox.currentText()
print value

answered Dec 02 '14 at 09:09

jatinkumar patel

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That's the label text, not the value. – mmitchell Feb 03 '15 at 02:18

score 3 · Answer 6 · answered Apr 12 '13 at 16:14

This is my OK code in QT 4.7:

 //add combobox list 
    QString val;
   ui->startPage->clear();
    val = "http://www.work4blue.com";
    ui->startPage->addItem(tr("Navigation page"),QVariant::fromValue(val));
    val = "https://www.google.com";
    ui->startPage->addItem("www.google.com",QVariant::fromValue(val));
    val = "www.twitter.com";
    ui->startPage->addItem("www.twitter.com",QVariant::fromValue(val));
    val = "https://www.youtube.com";
    ui->startPage->addItem("www.youtube.com",QVariant::fromValue(val));

   // get current value
    qDebug() << "current value"<< 
       ui->startPage->itemData(ui->startPage->currentIndex()).toString();

score 1 · Answer 7 · answered Mar 01 '15 at 18:27

I'm astonished that there isn't an activated signal and have the same problem. I solved it by making a subclass of QComboBox. I think it's better to avoid having to directly access the object and call its functions because that means more tight coupling and goes against Qt's philosophy. So here's the class I made that works for me.

class SmartComboBox : public QComboBox {

    Q_OBJECT

private slots:

    void triggerVariantActivated(int index);

public:

    SmartComboBox(QWidget *parent);

signals:

    void activated(const QVariant &);

};

And the implementation

void SmartComboBox::triggerVariantActivated(int index)
{
    activated(itemData(index));
}

SmartComboBox::SmartComboBox(QWidget *parent)
:QComboBox(parent)
{
    connect(this, SIGNAL(activated(int)), this, SLOT(triggerVariantActivated(int)));
}

score 1 · Answer 8 · edited Nov 29 '19 at 09:30

1

The question is old, but maybe, somebody need an actual answer.

In the QGIS 3.4 you can get the value from the QComboBox with the method currentData().

Example: comboBox.currentData()

Link: https://doc.qt.io/qt-5/qcombobox.html#currentData-prop

edited Nov 29 '19 at 09:30

Nils

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answered Nov 29 '19 at 08:49

deit

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score 0 · Answer 9 · answered Oct 23 '17 at 17:40

I did this

QDir path("/home/user/");
QStringList _dirs = path.entryList(QDir::Dirs);
std::cout << "_dirs_count = " << _dirs.count() << std::endl;
ui->cmbbox->addItem(Files);
ui->cmbbox->show();

You will see with this that the QStringList named _dirs is structured like an array whose members you can access via an index up to the value returned by _dirs.count()

score -1 · Answer 10 · answered May 09 '13 at 15:47

-1

I had the issue and

QString str = m_UI->myComboBox->currentText();

solved this.

answered May 09 '13 at 15:47

kiriloff

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Again, as others wrote above, this is *selected text*, NOT *selected VALUE*. A different thing. – Oak_3260548 Dec 30 '20 at 08:08

score -1 · Answer 11 · answered Sep 01 '16 at 07:07

-1

if you are developing QGIS plugins then simply

self.dlg.cbo_load_net.currentIndex()

answered Sep 01 '16 at 07:07

Abhijit Gujar

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Nope, this is as well not *selected `VALUE`*. Selected *`TEXT`*, selected *`VALUE`* and selected *`INDEX`* are completely different things. Only in a coincidence may `index` be equal to `value`. If people want to use combo, they need to learn and understand the difference. And to my best understanding, in Qt the VALUE is a bit extended when using data models. – Oak_3260548 Dec 30 '20 at 08:13

score -2 · Answer 12 · answered Jun 27 '16 at 08:08

-2

I know I'm very late but for those who still have that problem, it can be solved easily. I use Qt 5.3 and it works fine. No need to create a function or all that.

int valueComboBox;
valueComboBox = comboBox->currentIndex();

and it works ! Hope it helps !

answered Jun 27 '16 at 08:08

Alioum Serouis

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index is not the same as value – MoonBun Jul 05 '16 at 08:38

score -5 · Answer 13 · edited Mar 28 '11 at 04:53

-5

I confirm the easiest way is to do this:

uiAnalyseAssets::AnalyseAssets(QWidget *parent)
: QWidget(parent)
{
ui.comboBox->addItem("text1");
ui.comboBox->addItem("text2");

...
}

void mainFunction::yourFunction( int index )
{
 int value = ui.comboBox->currentText();
}

edited Mar 28 '11 at 04:53

Brad Mace

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answered Mar 27 '11 at 23:03

Tarik

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Wait a second -- doesn't `QComboBox::currentText()` return a `QString`? How do you arrive at a sensible `int`? And what do you want to do with your parameter `int index`? – Christian Severin May 03 '11 at 12:07

How can I get the selected VALUE out of a QCombobox?

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