void MainWindow::MakineStatR(int realStat) { QTimer::singleShot(150, this, SLOT(MakineStatR1));}

gfxx

{ubuntu 14.04 Qt5.6} In my main I have these fun:

I use directly in


MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

some other QTimer::singleshot with succes (there is not a "classic" QOBJECT related issue.... )

but in other sub-fun ... example:

void MainWindow::MakineStatR(int realStat) { QTimer::singleShot(150, this, SLOT(MakineStatR1));}
void MainWindow::MakineStatR1() { emit sendInOutMachine(45); }

not work at all and return these error:

QObject::connect: Parentheses expected, slot MainWindow::MakineStatR1 in ...
QObject::connect:  (receiver name: 'MainWindow')

Why these??

Regards
Giorgio

p3c0

Hi @gfxx ,
As exactly the error says you are missing the parentheses in here:
{ QTimer::singleShot(150, this, SLOT(MakineStatR1));}
Should be
{ QTimer::singleShot(150, this, SLOT(MakineStatR1()));}

Btw. you can use C++11 features to avoid the parentheses.

QTimer::singleShot(150, this, &MainWindow::MakineStatR1)

gfxx

sorry.... an stupyd error during test ..... the error show me with the Parentheses is :

QObject::connect: object not sxist ... or similar ...

(sorry now im out of office )
referred to the fact that Void not exist in MaiWindows ..... but it exist .... and Q_OBJECT is declared in mainwindows.h....

today i think can post the right error show

regards
giorgio

p3c0

@gfxx Alright, Post the exact error.

gfxx

@p3c0 real code with problem

void MainWindow::MakineStatR(int realStat) { QTimer::singleShot(150, this, SLOT(MakineStatR1(realStat)));}
void MainWindow::MakineStatR1(int realS1) { emit sendInOutMachine(realS1); }

real error ...

QObject::connect: No such slot MainWindow::MakineStatR1(realStat) in ../KYC-C/mainwindow.cpp:1862
QObject::connect:  (receiver name: 'MainWindow')
thread5 command:   101

yesterday i've test without passing int value to void..... it works..... with value passing i receive these error.....

regards
giorgio

mrjj

@gfxx said:
Hi
The timeout() signal of QTimer do not take a parameter
so
void MainWindow::MakineStatR(int realStat) {
QTimer::singleShot(150, this, SLOT(MakineStatR1(realStat)));
}

Is not possible as QTimer then would have to store your
realStat and use that in its timeout(). If it had a paramter.

So in short you cannot pass parameters that way as far as i know :)

Chris Kawa

realStat is a state. The timer will fire after some time (after you left the scope of realStat), so you need to preserve that state somewhere. You can use a lambda object for that:

void MainWindow::MakineStatR(int realStat) {
    QTimer::singleShot(150, [=]{ MakineStatR1(realStat); });
}

gfxx

@Chris-Kawa said:

realStat is a state. The timer will fire after some time (after you left the scope of realStat), so you need to preserve that state somewhere. You can use a lambda object for that:

realStat is the number of modbus register that i call for cofirm after sending modbus command. after every sending command (from pusch button in gui) i control the execution via register. my gui is client modbus that control remote machine (server).
I need to send command from a void and request of machineStat from other one valid for all command and calling from pushbutton void.....

regards
giorgio