Qt Network Chat

[Vivek1982]

Dear All,

I'm new to Qt. I have installed Qt version 4.6.1 in my Windows PC. I need to develop a application, where I need to chat as well as I need to update some info in some Lineedits in my network connected PC. Initially I need to develop a simple chat window where I can send msgs to my peer PC. How this can be done.please support me..

Thanks in advance

[Gokulnathvc]

Kindly look at this : http://thesmithfam.org/blog/2009/07/...-chat-program/

[Vivek1982]

thanks for fast reply.. I have gone thru the example.. Please can u suggest me code with simple comments or article. Where I can understand what is Socket programming in Qt. what are the procedures in code to be written in Prog to develop my own applications. It will be helpfull for me, If im getting any doc with how socket programming can be implemented in Qt.

[wagmare]

. Please can u suggest me code with simple comments or article. Where I can understand what is Socket programming in Qt

use these simple client/server program in qt
http://harmattan-dev.nokia.com/docs/...uneserver.html
http://harmattan-dev.nokia.com/docs/...uneclient.html
more simple than others for beginner ..

[Vivek1982]

Hi wagmare...

The site/link which u have sent is down. Its not accessible. Kindly suggest alternate way to get the same page or code.

[wagmare]

yeah me too .. yesterday it was working! .. some problem with the doc.trolltech server i guess ..
go to ur qt-assistant and search for
Fortune Server Example and Fortune Client Example

[Vivek1982]

Hi Wagmare..
Thanks for your reply. I have tried out a simple code where it sends simple qDebug msgs to compile output.I'm attaching code here.please go thru this and let me know.Im running a server code and client code at a time on same PC, my PC is connected to LAN(192.168.64.55). The moment I run client code. New connection is getting added and its printing qDebug msgs. please go thru the code. I feel problem may be at two points .one is at declaration socket QHostAddress and next is at main.cpp file where instead of default w.show(), listen()/connect to server().

TCPSERVER main.cpp
#include <QtGui/QApplication>
#include "server.h"

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
server w;
//w.show();
w.listen();

return a.exec();
}


TCPSERVER server.cpp
#include "server.h"
#include <QTcpServer>
#include <QTcpSocket>
#include <cstdio>

server::server(QWidget *parent)
: QMainWindow(parent)
{
server1 = new QTcpServer(this);
connect(server1, SIGNAL(newConnection()),
this, SLOT(on_newConnection()));
qDebug("new socket created");

}

server::~server()
{

}
void server::listen()
{
server1->listen(QHostAddress::LocalHost, 1234);
qDebug("Listening for new connection");

}
void server:n_newConnection()
{
socket = server1->nextPendingConnection();
qDebug("new connection established");
if(socket->state() == QTcpSocket::ConnectedState)
{
printf("New connection established.\n");
}
connect(socket, SIGNAL(disconnected()),
this, SLOT(on_disconnected()));
connect(socket, SIGNAL(readyRead()),
this, SLOT(on_readyRead()));
}
void server:n_readyRead()
{
while(socket->canReadLine())
{
QByteArray ba = socket->readLine();
if(strcmp(ba.constData(), "!exit\n") == 0)
{
socket->disconnectFromHost();
break;
}
printf(">> %s", ba.constData());
}
}
void server:n_disconnected()
{
printf("Connection disconnected.\n");
disconnect(socket, SIGNAL(disconnected()));
disconnect(socket, SIGNAL(readyRead()));
socket->deleteLater();
}


TCPSERVER server.h
#ifndef SERVER_H
#define SERVER_H

#include <QtGui/QMainWindow>
#include <QObject>

class QTcpServer;
class QTcpSocket;

class server : public QMainWindow
{
Q_OBJECT

public:
server(QWidget *parent = 0);
void listen();
~server();
public slots:
void on_newConnection();
void on_readyRead();
void on_disconnected();

private:
QTcpServer *server1;
QTcpSocket *socket;
};

#endif // SERVER_H

Hi Wagmare..
Thanks for your reply. I have tried out a simple code where it sends simple qDebug msgs to compile output.I'm attaching code here.please go thru this and let me know.Im running a server code and client code at a time on same PC, my PC is connected to LAN(192.168.64.55). The moment I run client code. New connection is getting added and its printing qDebug msgs. please go thru the code. I feel problem may be at two points .one is at declaration socket QHostAddress and next is at main.cpp file where instead of default w.show(), listen()/connect to server().
TCPCLIENT main.cpp
#include <QtGui/QApplication>
#include "client.h"

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
client w;
//w.show();
w.connectToserver();
return a.exec();
}


TCPCLIENT client.cpp

#include "client.h"
#include <QTcpSocket>
#include <QHostAddress>
#include <cstdio>


client::client(QWidget *parent)
: QMainWindow(parent)
{
socket = new QTcpSocket(this);
connect(socket, SIGNAL(connected()),
this, SLOT(on_connected()));
}

client::~client()
{

}
void client::connectToserver()
{
socket->connectToHost(QHostAddress::LocalHost, 1234);
qDebug("START PACKET SENDING");
}

void client:n_connected()
{
printf("Connection established.\n");
char buffer[1024];
forever
{
printf(">> ");
gets(buffer);
int len = strlen(buffer);
buffer[len] = '\n';
buffer[len+1] = '\0';
socket->write(buffer);
socket->flush();
}
}


TCPCLIENT client.h
#ifndef CLIENT_H
#define CLIENT_H

#include <QtGui/QMainWindow>
#include <QObject>

class QTcpSocket;

class client : public QMainWindow
{
Q_OBJECT

public:
client(QWidget *parent = 0);
void connectToserver();
~client();

private:
QTcpSocket *socket;
public slots:
void on_connected();

};

#endif // CLIENT_H

[wagmare]

sow ur .pro file .. did u added QT += network in it ..?

[Vivek1982]

Yes Wagmare. I have added initially only when creating the project. I'm posting the code of the Both files . I feel, problem may be the code or bcoz of I'm running on the LAN. I'm not sure of this. IP address QHostaddress also.
#-------------------------------------------------
#
# Project created by QtCreator 2013-09-25T13:28:55
#
#-------------------------------------------------

QT += network

TARGET = TcpServer
TEMPLATE = app


SOURCES += main.cpp\
server.cpp

HEADERS += server.h


#-------------------------------------------------
#
# Project created by QtCreator 2013-09-25T17:12:05
#
#-------------------------------------------------

QT += network

TARGET = TcpClient
TEMPLATE = app


SOURCES += main.cpp\
client.cpp

HEADERS += client.h

[wagmare]

for u

in .h

#include <QWidget>
#include <QLineEdit>
#include <QPushButton>
 
class QTcpSocket;
 
class TCPClient : public QWidget
{
    Q_OBJECT
 
public:
    TCPClient(QWidget *parent =0);
 
 
private slots:
    void on_connected();
    void connectToServer();
    void writeMessage();
 
 
private:
    QLineEdit *m_lineEdit;
    QPushButton *m_button;
    QPushButton *m_sendButton;
    QTcpSocket *m_socket;
};

#include <QWidget>
#include <QLineEdit>
#include <QPushButton>

class QTcpSocket;

class TCPClient : public QWidget
{
    Q_OBJECT

public:
    TCPClient(QWidget *parent =0);


private slots:
    void on_connected();
    void connectToServer();
    void writeMessage();


private:
    QLineEdit *m_lineEdit;
    QPushButton *m_button;
    QPushButton *m_sendButton;
    QTcpSocket *m_socket;
};

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#include <QtGui>
#include <QTcpSocket>
#include <QHostAddress>
#include <QDebug>
 
#include "TCPClient.h"
 
TCPClient::TCPClient(QWidget *parent)
    : QWidget(parent)
{
    m_lineEdit = new QLineEdit();
    m_button = new QPushButton("Connect");
    m_sendButton = new QPushButton("Send");
    m_sendButton->setEnabled(false);
    connect(m_button,SIGNAL(clicked()), this,SLOT(connectToServer()));
    connect(m_sendButton, SIGNAL(clicked()), this, SLOT(writeMessage()));
    m_socket = new QTcpSocket;
    connect(m_socket, SIGNAL(connected()), this, SLOT(on_connected()));
 
    QHBoxLayout *hLayout = new QHBoxLayout;
    hLayout->addWidget(m_button);
    hLayout->addWidget(m_sendButton);
 
    QVBoxLayout *mLayout = new QVBoxLayout;
    mLayout->addWidget(m_lineEdit);
    mLayout->addLayout(hLayout);
 
    this->setLayout(mLayout);
}
 
void
TCPClient::on_connected()
{
    qDebug()<<"Debug Connection established:";
    m_sendButton->setEnabled(true);
 
 
}
 
void
TCPClient::writeMessage()
{
    QString writeData = this->m_lineEdit->text();
 
    m_socket->write(writeData.toStdString().c_str());
    m_socket->flush();
}
 
 
void
TCPClient::connectToServer()
{
    m_socket->connectToHost(QHostAddress::LocalHost, 1234);
 
}

#include <QtGui>
#include <QTcpSocket>
#include <QHostAddress>
#include <QDebug>

#include "TCPClient.h"

TCPClient::TCPClient(QWidget *parent)
    : QWidget(parent)
{
    m_lineEdit = new QLineEdit();
    m_button = new QPushButton("Connect");
    m_sendButton = new QPushButton("Send");
    m_sendButton->setEnabled(false);
    connect(m_button,SIGNAL(clicked()), this,SLOT(connectToServer()));
    connect(m_sendButton, SIGNAL(clicked()), this, SLOT(writeMessage()));
    m_socket = new QTcpSocket;
    connect(m_socket, SIGNAL(connected()), this, SLOT(on_connected()));

    QHBoxLayout *hLayout = new QHBoxLayout;
    hLayout->addWidget(m_button);
    hLayout->addWidget(m_sendButton);

    QVBoxLayout *mLayout = new QVBoxLayout;
    mLayout->addWidget(m_lineEdit);
    mLayout->addLayout(hLayout);

    this->setLayout(mLayout);
}

void
TCPClient::on_connected()
{
    qDebug()<<"Debug Connection established:";
    m_sendButton->setEnabled(true);


}

void
TCPClient::writeMessage()
{
    QString writeData = this->m_lineEdit->text();

    m_socket->write(writeData.toStdString().c_str());
    m_socket->flush();
}


void
TCPClient::connectToServer()
{
    m_socket->connectToHost(QHostAddress::LocalHost, 1234);

}

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and main

#include <QApplication>
 
#include "TCPClient.h"
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    TCPClient c;
 
    c.show();
    return a.exec();
}

#include <QApplication>

#include "TCPClient.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    TCPClient c;

    c.show();
    return a.exec();
}

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use this client ..

[Vivek1982]

Hi. wagmare.. Thanks for the code.. I will try in my PC and let you know the result. Any changes to made in TCP server.h/cpp/main.cpp or let that remain same as mentioned above discussions.

Thanks alot wagmare