Why in class QTcpServer slot incomingConnection that is override virtual not works?

stackprogramer

Why in class QTcpServer slot incomingConnection that overrides virtual not works?

I used this tutorial( Multithread Client/Server) to create qtcpsocket. But when I send a message from the client to the server the connection is not starting... I expect when a connection is received in a different thread qtcpsocket is connected and prints the message of the client.
Thanks in advance

// myserver.h

#ifndef MYSERVER_H
#define MYSERVER_H

#include <QTcpServer>
#include <QDebug>
#include "mythread.h"

class MyServer : public QTcpServer
{
    Q_OBJECT
public:
    explicit MyServer(QObject *parent = 0);
    void StartServer();
    
signals:
    
public slots:

protected:
    void incomingConnection(int socketDescriptor);
    
};

#endif // MYSERVER_H

// myserver.cpp

#include "myserver.h"

MyServer::MyServer(QObject *parent) :
    QTcpServer(parent)
{
}

void MyServer::StartServer()
{
    if(!this->listen(QHostAddress::Any,1234))
    {
        qDebug() << "Could not start server";
    }
    else
    {
        qDebug() << "Listening...";
    }
}

void MyServer::incomingConnection(int socketDescriptor)
{
    qDebug() << socketDescriptor << " Connecting...";
    MyThread *thread = new MyThread(socketDescriptor, this);
    connect(thread, SIGNAL(finished()), thread, SLOT(deleteLater()));
    thread->start();
}

stackprogramer

Finally, I change the definition and declaration of incomingConnection slot according to below now everything is ok...

#ifndef MYSERVER_H
#define MYSERVER_H

#include <QTcpServer>
#include <QDebug>
#include "mythread.h"

class MyServer : public QTcpServer
{
    Q_OBJECT
public:
    explicit MyServer(QObject *parent = 0);
    void StartServer();
    
signals:
    
public slots:

protected:
    void incomingConnection(qint64 socketDescriptor);
    
};

#endif // MYSERVER_H

#include "myserver.h"

MyServer::MyServer(QObject *parent) :
    QTcpServer(parent)
{
}

void MyServer::StartServer()
{
    if(!this->listen(QHostAddress::Any,1234))
    {
        qDebug() << "Could not start server";
    }
    else
    {
        qDebug() << "Listening...";
    }
}

void MyServer::incomingConnection(qint64 socketDescriptor)
{
    qDebug() << socketDescriptor << " Connecting...";
    MyThread *thread = new MyThread(socketDescriptor, this);
    connect(thread, SIGNAL(finished()), thread, SLOT(deleteLater()));
    thread->start();
}

J.Hilk

@stackprogramer please, when you override something, use the override keyword! the compiler would have told you, that you're trying the override a function, that does not exist/is not virtual.

The function declaration is:

void QTcpServer::incomingConnection(qintptr)

which is clearly different from your

MyServer::incomingConnection(int)

stackprogramer

I have downloaded this example from the site I mentioned in the link. With these interpretations, what changes should I make in the code in order for data to arrive and a new thread to be executed?

I saw this tutorial, override base function is the same as it is done in up example...
https://www.programiz.com/cpp-programming/function-overriding

J.Hilk

@stackprogramer

void incomingConnection(qintptr socketDescriptor) override;

the original creator did it "wrong" as well, no override mark, and int instead of qintptr, which was probably fine for him at the time.

stackprogramer

Finally, I change the definition and declaration of incomingConnection slot according to below now everything is ok...

#ifndef MYSERVER_H
#define MYSERVER_H

#include <QTcpServer>
#include <QDebug>
#include "mythread.h"

class MyServer : public QTcpServer
{
    Q_OBJECT
public:
    explicit MyServer(QObject *parent = 0);
    void StartServer();
    
signals:
    
public slots:

protected:
    void incomingConnection(qint64 socketDescriptor);
    
};

#endif // MYSERVER_H

#include "myserver.h"

MyServer::MyServer(QObject *parent) :
    QTcpServer(parent)
{
}

void MyServer::StartServer()
{
    if(!this->listen(QHostAddress::Any,1234))
    {
        qDebug() << "Could not start server";
    }
    else
    {
        qDebug() << "Listening...";
    }
}

void MyServer::incomingConnection(qint64 socketDescriptor)
{
    qDebug() << socketDescriptor << " Connecting...";
    MyThread *thread = new MyThread(socketDescriptor, this);
    connect(thread, SIGNAL(finished()), thread, SLOT(deleteLater()));
    thread->start();
}