QT Network Download Example does not run in parallel！

Limo

void DownloadManager::progress(qint64 done, qint64 total)
{
QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
QUrl url = reply->url();
QFileInfo info(QString(url.toEncoded().constData()));
qDebug()<<info.fileName()<<done<<total;
}

connect(reply,SIGNAL(downloadProgress(qint64,qint64)),this,SLOT(progress(qint64,qint64)));

i write like this. It seems like to output filename alternate.
But it didn't start next one until the current finish.

jsulm

@Limo You should show how you start those parallel downloads.

Limo

This post is deleted!

Limo

@jsulm
in the example http://doc.qt.io/qt-5/qtnetwork-download-main-cpp.html

void DownloadManager::execute()
{
   QStringList args = QCoreApplication::instance()->arguments();
   args.takeFirst();           // skip the first argument, which is the program's name
   if (args.isEmpty()) {
       printf("Qt Download example - downloads all URLs in parallel\n"
              "Usage: download url1 [url2... urlN]\n"
              "\n"
              "Downloads the URLs passed in the command-line to the local directory\n"
              "If the target file already exists, a .0, .1, .2, etc. is appended to\n"
              "differentiate.\n");
       QCoreApplication::instance()->quit();
       return;
   }
   foreach (QString arg, args) {
       QUrl url = QUrl::fromEncoded(arg.toLocal8Bit());
       doDownload(url);
   }
}

in this function,just instead the foreach with :

doDownload(url1);
doDownload(url2);

jsulm

This post is deleted!

jsulm

@Limo How big are the files?
How do you know it did not start second download while first one is running?

Limo

@jsulm
they are 50~60MB.
i wrote this function:

void DownloadManager::progress(qint64 done, qint64 total)
{
QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
QUrl url = reply->url();
QFileInfo info(QString(url.toEncoded().constData()));
qDebug()<<info.fileName()<<done<<total;
}

and

connect(reply,SIGNAL(downloadProgress(qint64,qint64)),SLOT(progress(qint64,qint64)));

if the second download has ran ,it may output its info.But i didn't saw the second download's info when the first is running.

jsulm

@Limo Where do you call

connect(reply,SIGNAL(downloadProgress(qint64,qint64)),SLOT(progress(qint64,qint64)));

Do you call it for all replies?

Limo

@jsulm

void DownloadManager::doDownload(const QUrl &url)
{
    QNetworkRequest request(url);
    QNetworkReply *reply = manager.get(request);

#ifndef QT_NO_SSL
    connect(reply, SIGNAL(sslErrors(QList<QSslError>)), SLOT(sslErrors(QList<QSslError>)));
#endif

    connect(reply,SIGNAL(downloadProgress(qint64,qint64)),SLOT(progress(qint64,qint64)));
    currentDownloads.append(reply);
}