QUdpSocket and readyRead signal

[iaguirre]

I have implemented a simple UDP server according the specifcations of QUdpSocket class (Qt 5.10.1).

But on my code, the readySignal never received. I try to send data to the udp server via nc util: echo "Hello" | nc -u localhost 1234

This is my code:

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    MyServer server;
    server.initSocket();
    return a.exec();
}

and MyServer class implementation:

MyServer::MyServer(QObject *parent) : QObject(parent)
{
}

void MyServer::initSocket()
{
    udpSocket = new QUdpSocket(this);
    if(!udpSocket->bind(QHostAddress::Any, 1234, QAbstractSocket::BindFlag::ShareAddress))
      {
          qDebug() << "bind error";
      }

      if(udpSocket->state() == QUdpSocket::BoundState)
          qDebug() << "GREAT!!!";

    connect(udpSocket, SIGNAL(readyRead()),
            this, SLOT(readPendingDatagrams()));
}

void MyServer::readPendingDatagrams()
{
    QByteArray Buffer;
    int bufSize = udpSocket->pendingDatagramSize();
    Buffer.resize(bufSize);

    QHostAddress sender;
    quint16 senderPort;
    udpSocket->readDatagram(Buffer.data(),Buffer.size(),&sender,&senderPort);

}

Any help would be appreciated.
Thanks,
IAE

[Edit aha_1980: Fixed typo in title]

[Pablo J. Rogina]

@iaguirre are you able to check your server is really listening on port 1234?

$ netstat | grep 1234

[iaguirre]

I have finally resolved the problem by makig the connect before the bind process. Now, it works!!

void MyServer::initSocket()
{
    udpSocket = new QUdpSocket(this);
    connect(udpSocket, SIGNAL(readyRead()),
            this, SLOT(readPendingDatagrams()));

    if(!udpSocket->bind(QHostAddress::Any, 1234, QAbstractSocket::BindFlag::ShareAddress))
      {
          qDebug() << "bind error";
      }

      if(udpSocket->state() == QUdpSocket::BoundState)
          qDebug() << "GREAT!!!";

}

[KroMignon]

Thank's a lot for sharing your workaround.. I've got same issue after updating my application from Qt 5.4.2 to 5.11.2!

Performing connect to QUdpSocket::readyRead() signal before doing QUdpSocket::bind() also resolve it for me!

Regards