7.10 实例：qt编写客户端程序.txt

qt的源代码

class Client : public QDialog
 {
     Q_OBJECT
 public:
     Client(QWidget *parent = 0);
 private slots:
     void requestNewFortune();
     void readFortune();
     void displayError(QAbstractSocket::SocketError socketError);
     void enableGetFortuneButton();
 private:
     QLabel *hostLabel;
     QLabel *portLabel;
     QLineEdit *hostLineEdit;
     QLineEdit *portLineEdit;
     QLabel *statusLabel;
     QPushButton *getFortuneButton;
     QPushButton *quitButton;
     QDialogButtonBox *buttonBox;
     QTcpSocket *tcpSocket;
     QString currentFortune;
     quint16 blockSize;
 };
 Client::Client(QWidget *parent)
     : QDialog(parent)
 {
     ...
     tcpSocket = new QTcpSocket(this);
 ...
     connect(tcpSocket, SIGNAL(readyRead()), this, SLOT(readFortune()));
     connect(tcpSocket, SIGNAL(error(QAbstractSocket::SocketError)),
     ...
 }
void Client::requestNewFortune()
 {
     getFortuneButton->setEnabled(false);
     blockSize = 0;
     tcpSocket->abort();
     tcpSocket->connectToHost(hostLineEdit->text(),
                              portLineEdit->text().toInt());
 }
void Client::displayError(QAbstractSocket::SocketError socketError)
 {
     switch (socketError) {
     case QAbstractSocket::RemoteHostClosedError:
         break;
     case QAbstractSocket::HostNotFoundError:
         QMessageBox::information(this, tr("Fortune Client"),
                                  tr("The host was not found. Please check the "
                                     "host name and port settings."));
         break;
     case QAbstractSocket::ConnectionRefusedError:
         QMessageBox::information(this, tr("Fortune Client"),
                                  tr("The connection was refused by the peer. "
                                     "Make sure the fortune server is running, "
                                     "and check that the host name and port "
                                     "settings are correct."));
         break;
     default:
         QMessageBox::information(this, tr("Fortune Client"),
                                  tr("The following error occurred: %1.")
                                  .arg(tcpSocket->errorString()));
     }
     getFortuneButton->setEnabled(true);
 }
 void Client::readFortune()
 {
     QDataStream in(tcpSocket);
     in.setVersion(QDataStream::Qt_4_0);
     if (blockSize == 0) {
         if (tcpSocket->bytesAvailable() < (int)sizeof(quint16))
             return;
         in >> blockSize;
     }
     if (tcpSocket->bytesAvailable() < blockSize)
         return;
 QString nextFortune;
     in >> nextFortune;
     if (nextFortune == currentFortune) {
         QTimer::singleShot(0, this, SLOT(requestNewFortune()));
         return;
     }
     currentFortune = nextFortune;
     statusLabel->setText(currentFortune);
     getFortuneButton->setEnabled(true);
 }
class Server : public QDialog
 {
     Q_OBJECT
 public:
     Server(QWidget *parent = 0);
 private slots:
     void sendFortune();
 private:
     QLabel *statusLabel;
     QPushButton *quitButton;
     QTcpServer *tcpServer;
     QStringList fortunes;
 };
 tcpServer = new QTcpServer(this);
     if (!tcpServer->listen()) {
         QMessageBox::critical(this, tr("Fortune Server"),
                               tr("Unable to start the server: %1.")
                               .arg(tcpServer->errorString()));
         close();
         return;
     }
     statusLabel->setText(tr("The server is running on port %1.\n"
                             "Run the Fortune Client example now.")
                          .arg(tcpServer->serverPort()));
 fortunes << tr("You've been leading a dog's life. Stay off the furniture.")
              << tr("You've got to think about tomorrow.")
              << tr("You will be surprised by a loud noise.")
              << tr("You will feel hungry again in another hour.")
              << tr("You might have mail.")
              << tr("You cannot kill time without injuring eternity.")
              << tr("Computers are not intelligent. They only think they are.");
void Server::sendFortune()
 {
     QByteArray block;
     QDataStream out(&block, QIODevice::WriteOnly);
     out.setVersion(QDataStream::Qt_4_0);
out << (quint16)0;
     out << fortunes.at(qrand() % fortunes.size());
     out.device()->seek(0);
     out << (quint16)(block.size() - sizeof(quint16));
     QTcpSocket *clientConnection = tcpServer->nextPendingConnection();
     connect(clientConnection, SIGNAL(disconnected()),
             clientConnection, SLOT(deleteLater()));
clientConnection->write(block);
     clientConnection->disconnectFromHost();
 }