Subclass of QTcpSocket not working properly under Linux

[ZZZCY]

I'm trying to run a code that can run correctly under Windows, but I find it can't run under Linux, the slot never triggered.
void MainWindow::slotNewConnection() {
while (tcpserver->hasPendingConnections()) {
QTcpSocket *tcp = tcpserver->nextPendingConnection();
TcpPlatformSocket *tcpsocket = new TcpPlatformSocket;
tcpsocket->setSocketDescriptor(tcp->socketDescriptor());
connect(tcpsocket,&TcpPlatformSocket::readyRead,this,&MainWindow::slotReadyRead);
TcpPlatformSocketList.append(tcpsocket);
mode = MODE_WAIT_TYPE;
}
}

void MainWindow::slotReadyRead() {
QObject* obj = sender();
TcpPlatformSocket* ptcpSocket = dynamic_cast<TcpPlatformSocket*>(obj);

QByteArray buffer = ptcpSocket->readAll();
for(int i=0; i<buffer.length(); i++){
    readStateMachine(ptcpSocket, buffer.at(i));
}

}

class TcpPlatformSocket : public QTcpSocket
{
Q_OBJECT
public:
explicit TcpPlatformSocket(QObject *parent = nullptr);
void setPlatformType(platform_t platformType);
platform_t getPlatformType();

private:
platform_t platformType;

};

[Christian Ehrlicher]

You copy the socket descriptor from one socket to another for no reason. Use the returned QTcpSocket instead creating a new one with the same socket descriptor.

[ZZZCY]

@Christian-Ehrlicher I want to use my TcpPlatformSocket instead of QTcpsocket

[JonB]

@ZZZCY
Since QTcpSocket *QTcpServer::nextPendingConnection() returns a base QTcpSocket created by Qt intrastructure I think you would have to override void QTcpServer::incomingConnection(qintptr socketDescriptor) and create your own to achieve that.

In which case it may not be worth the effort subclassing to create your own? Maybe your TcpPlatformSocket could just encapsulate instead?

[ZZZCY]

@JonB Thanks for your reply, I solved the problem according to your description