QTcpSocket not emit any error or connected signals

Question

I have a small project which send some data over network using QTcpSocket. The server works fine but the client(code here) seems does nothing. If I set breakpoint at tcpSocket.connectToHost("127.0.0.1",port); it does jump in, but not any slots I defined.

I can't figure out what's wrong. I think the environment is ok because I can build 2 working examples from Qt GUI Programming

Any ideas are appreciated.

Hey, someone voted down please tell me why, so at least I don't have the same mistake? — Tiana987642, May 16 '15 at 12:41
The minimum case to reproduce the problem must be a part of the question. Your question has been likely downvoted as a link-only question. — Kuba hasn't forgotten Monica, May 18 '15 at 13:55

score 3 · Accepted Answer · answered May 16 '15 at 12:07

You do not have a QApplication instance and thus no event loop which does all the event / signal&slot handling.

So you at least need a QCoreApplication instance like this in main.cpp:

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    Client client;
    client.connectToServer();

    return a.exec();
}

QTcpSocket not emit any error or connected signals

1 Answers1