questions about qtcpserver and socket in Loopback Example

SpartaWHY117

Loopback Example tell me how to use qtcpsever and qtcpsocket. but i have a question in this example .

in start function:

 while (!tcpServer.isListening() && !tcpServer.listen()) {
        QMessageBox::StandardButton ret = QMessageBox::critical(this,
                                        tr("Loopback"),
                                        tr("Unable to start the test: %1.")
                                        .arg(tcpServer.errorString()),
                                        QMessageBox::Retry
                                        | QMessageBox::Cancel);
        if (ret == QMessageBox::Cancel)
            return;
    }

this while function doesn't block the program ? can just write like this ?

tcpServer.listen() ;
tcpServer.isListening();

in acceptConnection function :

 tcpServerConnection = tcpServer.nextPendingConnection();
    connect(tcpServerConnection, SIGNAL(readyRead()),
            this, SLOT(updateServerProgress()));
    connect(tcpServerConnection, SIGNAL(error(QAbstractSocket::SocketError)),
            this, SLOT(displayError(QAbstractSocket::SocketError)));

    serverStatusLabel->setText(tr("Accepted connection"));
    tcpServer.close();

after connect operation , tcpserver just be closed , what if the transfer not finished ? why the documentary write like this ?

SGaist

Hi,

QMessageBox::critical will spin an event loop like QDialog::exec() does hence the application continues to run.
The server is closed but the connection is still opened and the transfer is done between the two QTcpSocket.

SpartaWHY117

@SGaist said in questions about qtcpserver and socket in Loopback Example:

Hi,

QMessageBox::critical will spin an event loop like QDialog::exec() does hence the application continues to run.

The server is closed but the connection is still opened and the transfer is done between the two QTcpSocket.

thanks for your answer , the serve is closed means that this only accept one connection ?

i have a feature want to achieve is like this example , my program has a backup feature , it use timer to control fixed time interval to transfer some files to same program on the other machine . so if once connection connect , i close the tcpserver , which signal i can use to let me known the transfer finished ? or just set the total size to control ?

SGaist

That's up to you to implement since you know what you are transferring. You can use QDataStream::startTransaction for that.