QObject::connect: Cannot queue arguments of type 'QMap<QString,int>

RahibeMeryem

Hi,

I want to use

QMap<QString,int>

in my signal slot system

but it gives :

QObject::connect: Cannot queue arguments of type 'QMap<QString,int>&'
(Make sure 'QMap<QString,int>&' is registered using qRegisterMetaType().)

even I declared in main.cpp

    qRegisterMetaType<QMap<QString, int>>("QMap<QString, int>");

why its now working ? any idea ?

JonB

@RahibeMeryem
Presumably for the message you need

qRegisterMetaType<QMap<QString, int>&>("QMap<QString, int>&");

though I don't know why, that depends on what you have in your code.

mrjj

Hi
Can you show the full code ?

If i do

class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();
    
    QMap<QString, int> data; // the actual list
    
private slots:
    void myslot( QMap<QString, int> &p) // slot
    {
        p["test"] = 10;
    }
signals:
    void mysignal( QMap<QString, int> &p); // signal
private:
    Ui::MainWindow *ui;

};

and then in ctor

   connect(this, &MainWindow::mysignal, this, &MainWindow::myslot);
   emit mysignal(data);

it works as expected and i dont get the "Cannot queue arguments"

So are you trying to send signal to/from a other thread `?
or in which way does your code differ ?