How to match different paras for signal and slots using new functional-style "connect"?

goldenhawking

Hello !
In Qt4, we know that we can connect a signal which have more parameters than a slot :

connect(timer, SIGNAL(timeout()), widget, SLOT(update()));

timer is a QTimer object pointer, and widget is a QWidget.

However , it seems that new functional style connect requires signal and slot functions have same parameters table.

connect (timer, &QTimer::timeout, widget, &MyWidget::update);

The code above fired a compiler error, that is caused by Exact Match Parameter Table.

Question1:
For qt5 new functional style connect, how to deal with function overload and different paras connection?
Question2:
Will old style connect (using marco) be supported in future?

Thanks!

joeQ

@goldenhawking Hi,friend. Welcome.

You can see this thread About signal and slots in Qt4 and Qt5.

If I remember correctly, you should be a Chinese teacher. So, i find Chinese blog from cnblog for you. cnblog Qt Signal and slot.

End, if you want to get more information, you could search signal and slot in Qt help manual.

goldenhawking

@joeQ said in How to match different paras for signal and slots using new functional-style "connect"?:

cnblog

thanks！

mrjj

Will old style connect (using marco) be supported in future?

Maybe in some distant future it will be removed
but it will break heaps of code so i be surprised
if they removed anytime soon.

But it would make porting 4.X code to 5.X extra complicated so
i really doubt it will be removed in this decade.

The real benefit of the new syntax is that it fails at compile time and not
runtime.
Also Docs says

Connecting C++ Objects to QML Objects

The string-based syntax can connect C++ objects to QML objects, but the functor-based syntax cannot.

So that give me some reassurance as long as widgets exists.

http://doc.qt.io/qt-5/signalsandslots-syntaxes.html

goldenhawking

@mrjj said in How to match different paras for signal and slots using new functional-style "connect"?:

ome rea

Thank you very much of these answers!