Pass multiples arguments to a slot Qt

Question

I'm using a Qt horizontal slider and I want to connect its valueChanged signal to a slot I defined. However I need to access a specific member inside this slot to modify a variable thanks to the int I set with the slider. Until now, my connect line has looked like this:

connect(slider, SIGNAL(valueChanged(int)), this, SLOT(setVariable(int)));

Is it possible to pass more than one argument to my slot? What I'd like to do is something like:

connect(slider, SIGNAL(valueChanged(int)), this, SLOT(setVariable(int, pointerToMember*)));

If not how can I proceed?

Where does the value of `pointerToMember*` come from? If it's known at the time `connect` is called then you can use a capturing [`lambda`](https://doc.qt.io/qt-5/qobject.html#connect-4) as the slot. — G.M., Dec 04 '21 at 16:30
My pointer is defined in the same method from which I create this connect, a few lines before, so I guess I can try your suggestion — , Dec 04 '21 at 16:38

THE_CHOODICK · Answer 1 · 2022-02-06T10:58:50.993

2

Yes, you can, but you need to use new connect style, so you can pass lambda function

connect(slider, &QAbstractSlider::valueChanged, this, [=](int &new_value) { this->setVariable(new_value, ... );});

Edit: This works only in Qt5 and above

edited Feb 06 '22 at 10:58

answered Dec 04 '21 at 16:38

THE_CHOODICK

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Pass multiples arguments to a slot Qt

1 Answers1