Qt5 - Get Content Length while downloading a file from an Url - qt

Question

I am downloading an ".apk" file from a Url with Get method.
The file successfully donwload on my disk from the server.
I actually want to add a progressbar to my program. THE problem is : I can show the bytesReceived but I can't show the totalBytes of the file I am downloading (ContentLenth). How can I get it please from the server.
Here is what i get on my qDebug while downloading:
3498 of -1
799062 of -1
1923737 of -1
3037550 of -1
3200231 of 3200231
Here is my code:
void DownloadApk::LaunchDownload()
{
QNetworkProxy proxy;
proxy.setType(QNetworkProxy::HttpProxy);
proxy.setHostName("proxy");
proxy.setPort(8080);
QNetworkProxy::setApplicationProxy(proxy);
QUrl url("I put my Url here");
QNetworkRequest request(url);
_file = new QFile("C:/Users/Desktop/testdownload/downloadedFile.apk");
_file->open(QIODevice::WriteOnly);
QNetworkAccessManager *_manager= new QNetworkAccessManager;
_reply = _manager->get(request);// Manager is my QNetworkAccessManager
_file->write(_reply->readAll());
connect(_reply, SIGNAL(error(QNetworkReply::NetworkError)),
this, SLOT(error(QNetworkReply::NetworkError)));
connect(_reply, SIGNAL(downloadProgress(qint64, qint64)),
this, SLOT(updateProgress(qint64, qint64)));
connect(_reply, SIGNAL(finished()),
this, SLOT(finished()));
}
void DownloadApk::error(QNetworkReply::NetworkError err)
{qDebug() << err;
// Manage error here.
_reply->deleteLater();
}
void DownloadApk::updateProgress(qint64 read, qint64 total)
{
qDebug() << read <<"of"<<total ;
QByteArray b = _reply->readAll();
QDataStream out(_file);
out << b;
}
void DownloadApk::finished()
{
QMessageBox::information(this, tr("Complete"), tr("Successfully Downloaded"));
// Done
_reply->deleteLater();
_file->close();
// probably delete the file object too
}

Answer 1

I fixed the problem. Actually it was not a QT problem. This Qt code works correctly.
The probleme was from the server that wasn't sending ContentLenth on the header of the reply.