Qt 4.8: sender.cpp Example File (network/multicastsender/sender.cpp)

Qt Reference Documentation

# sender.cpp Example File

network/multicastsender/sender.cpp

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     #include <QtGui>
     #include <QtNetwork>

     #include "sender.h"

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

         statusLabel = new QLabel(tr("Ready to multicast datagrams to group %1 on port 45454").arg(groupAddress.toString()));

         ttlLabel = new QLabel(tr("TTL for multicast datagrams:"));
         ttlSpinBox = new QSpinBox;
         ttlSpinBox->setRange(0, 255);

         QHBoxLayout *ttlLayout = new QHBoxLayout;
         ttlLayout->addWidget(ttlLabel);
         ttlLayout->addWidget(ttlSpinBox);

         startButton = new QPushButton(tr("&Start"));
         quitButton = new QPushButton(tr("&Quit"));

         buttonBox = new QDialogButtonBox;
         buttonBox->addButton(startButton, QDialogButtonBox::ActionRole);
         buttonBox->addButton(quitButton, QDialogButtonBox::RejectRole);

         timer = new QTimer(this);
         udpSocket = new QUdpSocket(this);
         messageNo = 1;

         connect(ttlSpinBox, SIGNAL(valueChanged(int)), this, SLOT(ttlChanged(int)));
         connect(startButton, SIGNAL(clicked()), this, SLOT(startSending()));
         connect(quitButton, SIGNAL(clicked()), this, SLOT(close()));
         connect(timer, SIGNAL(timeout()), this, SLOT(sendDatagram()));

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

         setWindowTitle(tr("Multicast Sender"));
         ttlSpinBox->setValue(1);
     }

     void Sender::ttlChanged(int newTtl)
     {
         udpSocket->setSocketOption(QAbstractSocket::MulticastTtlOption, newTtl);
     }

     void Sender::startSending()
     {
         startButton->setEnabled(false);
         timer->start(1000);
     }

     void Sender::sendDatagram()
     {
         statusLabel->setText(tr("Now sending datagram %1").arg(messageNo));
         QByteArray datagram = "Multicast message " + QByteArray::number(messageNo);
         udpSocket->writeDatagram(datagram.data(), datagram.size(),
                                  groupAddress, 45454);
         ++messageNo;
     }