Qt Reference Documentation

- Qt 4.8
- ALL VERSIONS

- A
- A
- A
- Print

# receiver.cpp Example File

network/multicastreceiver/receiver.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2015 The Qt Company Ltd.
     ** Contact: http://www.qt.io/licensing/
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
     ** You may use this file under the terms of the BSD license as follows:
     **
     ** "Redistribution and use in source and binary forms, with or without
     ** modification, are permitted provided that the following conditions are
     ** met:
     **   * Redistributions of source code must retain the above copyright
     **     notice, this list of conditions and the following disclaimer.
     **   * Redistributions in binary form must reproduce the above copyright
     **     notice, this list of conditions and the following disclaimer in
     **     the documentation and/or other materials provided with the
     **     distribution.
     **   * Neither the name of The Qt Company Ltd nor the names of its
     **     contributors may be used to endorse or promote products derived
     **     from this software without specific prior written permission.
     **
     **
     ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
     **
     ** $QT_END_LICENSE$
     **
     ****************************************************************************/

     #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()));
         }
     }