Passing parmaterts to slot - what are the options ?

Anonymous_Banned275

        int index = 0;
        QAction *TESTMenu_aboutAct = BTMenu->addAction(tr("&Run btscanner "),
 //               this, &MainWindow::menu_slot_indexed(0););

                 this, [this]{menu_slot_indexed(0);});        works 
              this, [this]{menu_slot_indexed(index);});      does not compile 

        // NOTE will not allow to pass index as variable
                TESTMenu_aboutAct->setStatusTip(tr("Run bluetooth  (excample ) btscanner   menu_slot"));   TOK

The above has been posted as a solution to pass parameter to slot , sort off "half lambda" - BUT the (temporary fixed) parameter "o" cannot be passed as variable.
The intent is to have fixed menu options - index being as convenient addition distinction in the menus.

The pseudo code will look something like this

QAction *TESTMenu_aboutAct = BTMenu->addAction(tr("&Run btscanner "),

// this, &MainWindow::menu_slot_indexed(0););
QAction *TESTMenu_aboutAct = BTMenu->addAction(tr("&Run appliication xr "),
// this, &MainWindow::menu_slot_indexed(1););
QAction *TESTMenu_aboutAct = BTMenu->addAction(tr("&Run application y "),
// this, &MainWindow::menu_slot_indexed(2););

It makes the actual action goofy and almost defeats the notion to have a common, indexed slot function.

Is there any other way to "pass parameter" to slot - besides using "index" as global variable?

therefore not passed a slot parameter

J.Hilk

@AnneRanch there is no such thing as a "half lambda", please take your time and study the official source

https://en.cppreference.com/w/cpp/language/lambda

or study book or something to get a better concept of the stuff you use.

Is there any other way to "pass parameter" to slot - besides using "index" as global variable?

yes, capturing by copy.

this, [this, index]()->void{menu_slot_indexed(index);});

Anonymous_Banned275

@J-Hilk Sorry - I quoted a source , I did not invent the "half lambda". term. Good advise, but would be also good without the "RTFM:" I actually may need to pass more then just index...

J.Hilk

@AnneRanch

Sorry - I quoted a source , I did not invent the "half lambda".

nothing to feel sorry about.

I actually may need to pass more then just index...

Ehm, your example showed how to capture one variable this I showed you how to capture 2 variables - this and index- and gave you a link to the documentation....

You know, there are two types of people in this world:

Those who can extrapolate from incomplete data