Question

I am currently experiencing issues on a Qt thread.

I have to upload a list of files in a QThread, but apparently one upload doesn’t work and/or my slots are never called. If I put the methods out of the thread it works perfectly.

Here is the run() method :

void UploadThread::run()
{
    for (int i = 0; i < Window::_listUpload.size(); i++) {
        qDebug() << Window::_listUpload[i].getPath();
        this->sendFile(Window::_listUpload[i].getPath());
    }
}

Here is the sendFile() method :

void UploadThread::sendFile(const QString & path)
{
    QFreeDesktopMime mime;
    QNetworkAccessManager *manager = new QNetworkAccessManager;
    QFileInfo fInfo(path);
    QNetworkRequest request(QUrl("http://my-url/"));
    QNetworkReply *reply;

    QString bound = "---------------------------723690991551375881941828858";
    QByteArray data(QString("--"+bound+"\r\n").toAscii());
    data += "Content-Disposition: form-data; name=\"action\"\r\n\r\n";
    data += "\r\n";
    data += QString("--" + bound + "\r\n").toAscii();
    data += "Content-Disposition: form-data; name=\"file\"; filename=\""+fInfo.fileName()+"\"\r\n";
    data += "Content-Type: "+mime.fromFile(path)+"\r\n\r\n";

    QFile file(fInfo.absoluteFilePath());
    file.open(QIODevice::ReadOnly);
    data += file.readAll();
    data += "\r\n";
    data += QString("--" + bound + "\r\n").toAscii();
    data += QString("--" + bound + "\r\n").toAscii();
    data += "Content-Disposition: form-data; name=\"desc\"\r\n\r\n";
    data += "Description for my image here :)\r\n";
    data += "\r\n";
    request.setRawHeader(QString("Accept-Encoding").toAscii(), QString("gzip,deflate").toAscii());
    request.setRawHeader(QString("Content-Type").toAscii(),QString("multipart/form-data; boundary=" + bound).toAscii());
    request.setRawHeader(QString("Content-Length").toAscii(), QString::number(data.length()).toAscii());

    reply = manager->post(request, data);

    QObject::connect(reply, SIGNAL(uploadProgress(qint64,qint64)), currentThread(), SLOT(receiveUploadProgress(qint64, qint64)));
    QObject::connect(manager, SIGNAL(finished(QNetworkReply*)), currentThread(), SLOT(uploadFinished(QNetworkReply*)));
}

And here are my slots :

void UploadThread::uploadFinished(QNetworkReply *reply)
{
    _isFinished = true;
}

void UploadThread::receiveUploadProgress(qint64 bytesSent, qint64 bytesTotal)
{
    qDebug() << bytesSent << " " << bytesTotal;
}

Do you see a problem in my code ?
Thank you.

Answer 1

Ok, I get it.

For each upload, I need to start the QEventLoop using exec(), and at the end of an upload I have to use exit() in order to finish the QEventLoop. It now works like a charm.