Russian Qt Forum

void MainWindow::on_b_clicked()
{

    blockSize = 0;
    tcpSocket->abort();
    tcpSocket->connectToHost(ui->host->text(),
                             ui->port->text().toInt());
    connect(tcpSocket, SIGNAL(connected()), this, SLOT(sendMsg()));

}
void MainWindow::sendMsg()
{
    QByteArray block;
    QDataStream out(&block, QIODevice::WriteOnly);
    out.setVersion(QDataStream::Qt_4_7);
    out << (quint16)0;
    out << QString("hi");
    out.device()->seek(0);
    out << (quint16)(block.size() - sizeof(quint16));
    tcpSocket->write(block);
    while(tcpSocket->bytesToWrite() > 0)
    {
       tcpSocket->waitForBytesWritten();
    }
}

......
connect(tcpServer, SIGNAL(newConnection()), this, SLOT(handleConnection()));
.....
void MainWindow::handleConnection()
{
    QByteArray block;
    QDataStream out(&block, QIODevice::ReadWrite);


    out.setVersion(QDataStream::Qt_4_7);
    out << (quint16)0;
    out << QString("ok");
    out.device()->seek(0);
    out << (quint16)(block.size() - sizeof(quint16));
    QTcpSocket *clientConnection = tcpServer->nextPendingConnection();
    connect(clientConnection, SIGNAL(readyRead()),
            this, SLOT(slotReadClient()));



    connect(clientConnection, SIGNAL(disconnected()),
            clientConnection, SLOT(deleteLater()));

    clientConnection->write(block);
}
void MainWindow::slotReadClient()
{
    QTcpSocket* pClientSocket = (QTcpSocket*)sender();
    QByteArray msg = pClientSocket->readAll();

    QString msg_str(msg);
    this->addLog(msg_str);
}

 while(tcpSocket->bytesToWrite() > 0)
    {
       tcpSocket->waitForBytesWritten();
    }

   QByteArray block;
    QDataStream in(&block, QIODevice::ReadOnly);
     in.setVersion(QDataStream::Qt_4_7);
    quint16 vers;    
    QString str;
    in >> vers;
    in >> str;

    QDataStream in(&socket, QIODevice::ReadOnly);
     in.setVersion(QDataStream::Qt_4_7);
    quint16 vers;    
    QString str;
    in >> vers;
    in >> str;