Cascades Development

[Curahee]

Hey Developers

How can I pass a QList as an argument with a signal? He keeps saying

"No such signal ConnectionService::downloadCompleted(QList, QString)"

I'm emitting the signal with a QList<Connection*> object and a QString. This is my signal

void downloadCompleted(const QList<Connection*> &connections, const QString &error);

 And this is how I connect

connect(&this->connectionService, SIGNAL(downloadCompleted(QList, QString)), this, SLOT(searchCompleted(QList, QString)));

 I allso tried QList<Connection*> as SIGNAL signature. But that did not work either.

Thanks in advance.

[Zmey · Accepted solution]

Pass a complete type, i.e.

connect(&connectionService, SIGNAL(downloadCompleted(const QList<Connection*>&, const QString&)), this, SLOT(searchCompleted(const QList<Connection *>&, const QString&)));

"const" and "&" can be omitted so this should also work:

connect(&connectionService, SIGNAL(downloadCompleted(QList<Connection*>, QString)), this, SLOT(searchCompleted(QList<Connection *>, QString)));

upd:

Try registering the type:

qRegisterMetaType< QList<Connection *> >("QList<Connection *>");

[Curahee]

That's weird, I thought I allready tried that. But hey, it works, I'm happy .

Thanks again!

[Curahee]

And is it also possible to do it like this:

void downloadCompleted(const QList<Connection*> *connections, const QString &error);

connect(&connectionService, SIGNAL(downloadCompleted(QList<Connection*>*, QString)), this, SLOT(searchCompleted(QList<Connection*>*, QString)));

 Because that does not seem to work anymore. Don't know if it's possible to pass a pointer with a signal.

[Zmey]

Try registering QList<Connection *>* using qRegisterMetatype. It should work, but I think it's better to pass QList itself so you don't have to track it's lifetime.

Qt containers are copy-on-write anyway so this operation shouldn't be time consuming.

Even foreach() makes a copy of it's container before iteration.