Qt 4.8: receiver.cpp Example File (network/multicastreceiver/receiver.cpp)

Qt Reference Documentation

# receiver.cpp Example File

network/multicastreceiver/receiver.cpp

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     #include <QtGui>
     #include <QtNetwork>

     #include "receiver.h"

     Receiver::Receiver(QWidget *parent)
         : QDialog(parent)
     {
         groupAddress = QHostAddress("239.255.43.21");

         statusLabel = new QLabel(tr("Listening for multicasted messages"));
         quitButton = new QPushButton(tr("&Quit"));

         udpSocket = new QUdpSocket(this);
         udpSocket->bind(45454, QUdpSocket::ShareAddress);
         udpSocket->joinMulticastGroup(groupAddress);

         connect(udpSocket, SIGNAL(readyRead()),
                 this, SLOT(processPendingDatagrams()));
         connect(quitButton, SIGNAL(clicked()), this, SLOT(close()));

         QHBoxLayout *buttonLayout = new QHBoxLayout;
         buttonLayout->addStretch(1);
         buttonLayout->addWidget(quitButton);
         buttonLayout->addStretch(1);

         QVBoxLayout *mainLayout = new QVBoxLayout;
         mainLayout->addWidget(statusLabel);
         mainLayout->addLayout(buttonLayout);
         setLayout(mainLayout);

         setWindowTitle(tr("Multicast Receiver"));
     }

     void Receiver::processPendingDatagrams()
     {
         while (udpSocket->hasPendingDatagrams()) {
             QByteArray datagram;
             datagram.resize(udpSocket->pendingDatagramSize());
             udpSocket->readDatagram(datagram.data(), datagram.size());
             statusLabel->setText(tr("Received datagram: \"%1\"")
                                  .arg(datagram.data()));
         }
     }