7.13 实例：收发广播报文.txt

qt的源代码

 #ifndef RECEIVER_H
 #define RECEIVER_H
 #include <QDialog>
 class QLabel;
 class QPushButton;
 class QUdpSocket;
 class Receiver : public QDialog
 {
     Q_OBJECT
 public:
     Receiver(QWidget *parent = 0);
 private slots:
     void processPendingDatagrams();
 private:
     QLabel *statusLabel;
     QPushButton *quitButton;
     QUdpSocket *udpSocket;
 };
 #endif
 #include <QtGui>
 #include <QtNetwork>
 #include "receiver.h"
 Receiver::Receiver(QWidget *parent)
     : QDialog(parent)
 {
     statusLabel = new QLabel(tr("Listening for broadcasted messages"));
     quitButton = new QPushButton(tr("&Quit"));
 udpSocket = new QUdpSocket(this);
     udpSocket->bind(45454);
     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("Broadcast 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()));
     }
 }
 #include <QApplication>
 #include "receiver.h"
 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
     Receiver receiver;
     receiver.show();
     return receiver.exec();
 }
#ifndef SENDER_H
 #define SENDER_H
 #include <QDialog>
 class QDialogButtonBox;
 class QLabel;
 class QPushButton;
 class QTimer;
 class QUdpSocket;
class Sender : public QDialog
 {
     Q_OBJECT
 public:
     Sender(QWidget *parent = 0);
 private slots:
     void startBroadcasting();
     void broadcastDatagram();
 private:
     QLabel *statusLabel;
     QPushButton *startButton;
     QPushButton *quitButton;
     QDialogButtonBox *buttonBox;
     QUdpSocket *udpSocket;
  QTimer *timer;
     int messageNo;
 };
 #endif
#include <QtGui>
 #include <QtNetwork>
 #include "sender.h"
 Sender::Sender(QWidget *parent)
     : QDialog(parent)
 {
   statusLabel = new QLabel(tr("Ready to broadcast datagrams on port 45454"));
  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(startButton, SIGNAL(clicked()), this, SLOT(startBroadcasting()));
     connect(quitButton, SIGNAL(clicked()), this, SLOT(close()));
     connect(timer, SIGNAL(timeout()), this, SLOT(broadcastDatagram()));
QVBoxLayout *mainLayout = new QVBoxLayout;
     mainLayout->addWidget(statusLabel);
     mainLayout->addWidget(buttonBox);
     setLayout(mainLayout);
     setWindowTitle(tr("Broadcast Sender"));
 }
 void Sender::startBroadcasting()
 {
     startButton->setEnabled(false);
     timer->start(1000);
 }
 void Sender::broadcastDatagram()
 {
   statusLabel->setText(tr("Now broadcasting datagram %1").arg(messageNo));
     QByteArray datagram = "Broadcast message " + QByteArray::number(messageNo);
     udpSocket->writeDatagram(datagram.data(), datagram.size(),
                              QHostAddress::Broadcast, 45454);
     ++messageNo;
 }
#include <QApplication>
 #include "sender.h"
 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
     Sender sender;
     sender.show();
     return sender.exec();
 }