Signal slots question

ahura_24

hi everybody . i have one question

@
#include <QtGui>

void slt()
{
// do something
}

int main(int argc, char *argv[])
{
QApplication app(argc, argv);

QPushButton btn;

// connect btn signal(clicked()) to slt "function" !! i want connect to function not object!

return app.exec();

}
@

tnx for your help :)

Flurite

You must have a class that contains your slot, which is in this case, void slot(). Have you defined your class somewhere? If so, can we see it?

I'm no expert on this, but I think I may be able to help you here..

dbzhang800

What you need is some basic knowledge of Qt. And this will be useful for you www.catb.org/~esr/faqs/smart-questions.html

What you provided are some Qt4's code snippets, but your slt() is not a Qt SLOT at all!

However, you can do similar thing with Qt5 using the new SIGNAL & SLOT syntax.

Read the manual carefully.

ahura_24

if i have too many button or .... and i want define for them different slots , what i must to do ? i must declare to many class or one global class !! if i have too many button and for each of them has been one slot , how can i declare this ?!!

sierdzio

I think what you need is to:

learn better English

get some more practice in object oriented programming

rethink and rephrase your questions so that other people - who want to help you - can understand them clearly

read Qt documentation on "signal and slot mechanism":http://qt-project.org/doc/qt-4.8/signalsandslots.html, it's really well written.

The answer to your questions, as far as I can get what you mean, is this: you can declare multiple slots in a single class, and connect your button signals to them (that is more or less the standard practice), or create one slot and handle all signals there (this is ugly, I won't recommend).

About "how can I declare this"... really, really, DO read the docs. Here is a snippet:
@
public slots:
void mySlot();
@

And in source somewhere:
@
connect(someButton, SIGNAL(clicked()), someObject, SLOT(mySlot()));

.....

void MyClass::mySlot() {
/// code
}

@

giesbert

You can define one ore more classes with one or more slots.
signals of an object in Qt 4.x MUST be connected to a slot of an object. Whether you use one or more classes for the slots is up to you.

sierdzio

Damn, I do sound quite arrogant at times :( Sorry.

But I really mean it with reading the documentation.