QT中的网络编程实例

Qclient.h

/**************************************************************************** ** $Id: /sample/10/qclient.h 2.3.2 edited 2004-10-12 $

** https://www.360docs.net/doc/2c8487490.html,

** This file is part of an example program for Qt. This example

** program may be used, distributed and modified without limitation. **

*****************************************************************************/

#ifndef QCLIENT_H

#define QCLIENT_H

#include

class QClient : public QWidget

{

Q_OBJECT

public:

QClient(QWidget *parent = 0, const char *name = 0);

private slots:

void closeConnection();

void sendToServer();

void connectToServer();

void socketReadyRead();

void socketConnected();

void socketConnectionClosed();

void socketClosed();

void socketError(int);

private:

QSocket *socket;

QTextView *infoText;

QLineEdit *addrText;

QLineEdit *portText;

QLineEdit *inputText;

};

#endif //QCLIENT_H

Qclient.cpp

/**************************************************************************** ** $Id: /sample/10/qclient.h 2.3.2 edited 2004-10-12 $

** https://www.360docs.net/doc/2c8487490.html,

** This file is part of an example program for Qt. This example

** program may be used, distributed and modified without limitation. **

*****************************************************************************/ #include "qclient.h"

#include

QClient::QClient(QWidget *parent, const char *name)

: QWidget(parent, name)

{

infoText = new QTextView(this);

QHBox *hb = new QHBox(this);

inputText = new QLineEdit(hb);

QHBox *addrBox = new QHBox(this);

QLabel *ip = new QLabel("IP:", addrBox, "ip");

ip->setAlignment(1);

addrText = new QLineEdit(addrBox);

QLabel *port = new QLabel("PORT:", addrBox, "port");

port->setAlignment(1);

portText = new QLineEdit(addrBox);

QHBox *buttonBox = new QHBox(this);

// QPushButton *Connect = new QPushButton(tr("Connect"), this); QPushButton *send = new QPushButton(tr("Send"), hb); QPushButton *close = new QPushButton(tr("Close connection"), buttonBox);

QPushButton *quit = new QPushButton(tr("Quit"), buttonBox); QPushButton *Connect = new QPushButton(tr("Connect"), addrBox);

connect(send, SIGNAL(clicked()),

SLOT(sendToServer()) );

connect(close, SIGNAL(clicked()),

SLOT(closeConnection()) );

connect(quit, SIGNAL(clicked()),

qApp, SLOT(quit()) );

connect(Connect, SIGNAL(clicked()),

SLOT(connectToServer()) );

//create the socket and connect various of its signals

socket = new QSocket(this);

connect(socket, SIGNAL(connected()),

SLOT(socketConnected()) );

connect(socket, SIGNAL(connectionClosed()),

SLOT(socketConnectionClosed()) );

connect(socket, SIGNAL(readyRead()),

SLOT(socketReadyRead()) );

connect(socket, SIGNAL(error(int)),

SLOT(socketError(int)) );

QVBoxLayout *l = new QVBoxLayout(this);

l->addWidget(infoText, 10);

l->addWidget(hb, 1);

l->addWidget(addrBox, 1);

l->addWidget(buttonBox, 1);

// l->addWidget(Connect, 1);

// l->addWidget(close, 1);

// l->addWidget(quit, 1);

//connect to the server

infoText->append(tr("Tying to connect to the server"));

// socket->connectToHost(host, port);

}

void QClient::closeConnection()

{

socket->close();

if (QSocket::Closing == socket->state()) {

// We have a delayed close

connect(socket, SIGNAL(delayedCloseFinished()),

SLOT(socketClosed()));

} else {

// The socket is closed

socketClosed();

}

void QClient::sendToServer()

{

// write to the server

if (QSocket::Connected == socket->state()) {

QTextStream os(socket);

os << inputText->text() << "\n";

inputText->setText("");

} else {

// The socket is unconnected

infoText->append(tr("The server is lost\n"));

}

void QClient::connectToServer()

{

// connect to the server

socket->connectToHost(addrText->text(), (portText->text()).toInt()); }

void QClient::socketReadyRead()

{

// read from the server

while (socket->canReadLine()) {

infoText->append(socket->readLine());

}

void QClient::socketConnected()

{

infoText->append(tr("Connected to server\n"));

}

void QClient::socketConnectionClosed()

{

infoText->append(tr("Connection closed by the server\n"));

}

void QClient::socketClosed()

{

infoText->append(tr("Connection closed\n"));

}

void QClient::socketError(int e)

{

if (e == QSocket::ErrConnectionRefused) {

infoText->append(tr("Connection Refused\n"));

} else if (e == QSocket::ErrHostNotFound) {

infoText->append(tr("Host Not Found\n"));

} else if (e == QSocket::ErrSocketRead) {

infoText->append(tr("Socket Read Error\n"));

}

Main.cpp

/**************************************************************************** ** $Id: /sample/10/main.cpp 2.3.2 edited 2004-10-12 $

** https://www.360docs.net/doc/2c8487490.html,

** This file is part of an example program for Qt. This example

** program may be used, distributed and modified without limitation. **

*****************************************************************************/

#include

#include "qclient.h"

int main( int argc, char **argv )

{

QApplication app( argc, argv );

QClient *client = new QClient( 0 );

app.setMainWidget( client );

client->show();

int result = app.exec();

return result;

}

Server.cpp

/****************************************************************************

** $Id: qt/server.cpp 3.0.5 edited Oct 12 2001 $

** This file is part of an example program for Qt. This example

** program may be used, distributed and modified without limitation.

*****************************************************************************/

#include

The ClientSocket class provides a socket that is connected with a client.

For every client that connects to the server, the server creates a new

instance of this class.

class ClientSocket : public QSocket

{

Q_OBJECT

public:

ClientSocket( int sock, QObject *parent=0, const char *name=0 ) : QSocket( parent, name )

{

line = 0;

connect( this, SIGNAL(readyRead()), SLOT(readClient()) );

connect( this, SIGNAL(connectionClosed()), SLOT(connectionClosed()) );

setSocket( sock );

}

~ClientSocket()

{

}

private slots:

void readClient()

{

while ( canReadLine() ) {

QTextStream os( this );

os << line << ": " << readLine();

line++;

}

void connectionClosed()

{

delete this;

}

private:

int line;

};

The SimpleServer class handles new connections to the server. For every client that connects, it creates a new ClientSocket -- that instance is now responsible for the communication with that client.

class SimpleServer : public QServerSocket

{

Q_OBJECT

public:

SimpleServer( QObject* parent=0 ) :

QServerSocket( 4242, 1, parent )

{

if ( !ok() ) {

qWarning("Failed to bind to port 4242");

exit(1);

}

~SimpleServer()

{

}

void newConnection( int socket )

{

(void)new ClientSocket( socket, this );

emit newConnect();

}

signals:

void newConnect();

};

The ServerInfo class provides a small GUI for the server. It also creates the SimpleServer and as a result the server.

class ServerInfo : public QVBox

{

Q_OBJECT

public:

ServerInfo()

{

SimpleServer *server = new SimpleServer( this );

QString itext = QString(

"This is a small server example.\n"

"Connect with the client now."

);

QLabel *lb = new QLabel( itext, this );

lb->setAlignment( AlignHCenter );

infoText = new QTextView( this );

QPushButton *quit = new QPushButton( "Quit" , this );

connect( server, SIGNAL(newConnect()), SLOT(newConnect()) );

connect( quit, SIGNAL(clicked()), qApp, SLOT(quit()) );

}

~ServerInfo()

{

}

private slots:

void newConnect()

{

infoText->append( "New connection\n" );

}

private:

QTextView *infoText;

};

int main( int argc, char** argv )

{

QApplication app( argc, argv );

ServerInfo info;

app.setMainWidget( &info );

info.show();

return app.exec();

}

#include "server.moc"

以上四个文件，Qclient.h 、Qclient.cpp和Main.cpp 是客户端的程序编译后，在qvfb 上运行，Server.cpp为服务端，编译后，运行在Xwindows上。效果如下图。注：访问端口为：4242