Ahh sorry I thought an strace would help. It might take me a bit to get an actual stack trace as I'd have to set up my build environment with debugging symbols.

The reason I was recreating QNetworkAccessManager is because I was under the impression that I needed to do so when I lost network access (m_mgr->networkAccessible() != QNetworkAccessManager::Accessible). That's what a user said on this stack overflow post. Is that incorrect? If I could just used something like setNetworkAccessible() that would avoid this whole mess. I've tested out removing the QNAM deletion and the exception does not occur.

I guess I am sort of confused in general about what QNetworkAccessManager::NetworkAccessibility even represents? It's not going to alter the actual network state, NetworkManager handles that

Tested on another server, everything works fine

Another thing I notice is that QNetworkAccessManager manager is created just before the post request. This indicates to me that you are not handling any signal like finished(..). So how to you know that response has come back ?

Hi
fast sample.
it need error handling to be useful in real code ! ( dont skip that if for a real program)

#include <QApplication> #include <QDebug> #include <QJsonDocument> #include <QJsonObject> #include <QNetworkReply> #include <QNetworkAccessManager> int main(int argc, char* argv[]) { QApplication a(argc, argv); MainWindow w; w.show(); // if in mainwindow. make sure m_manager lives in .h as member. else it wont work. ( death by scope) QNetworkAccessManager m_manager; // make request QNetworkRequest request = QNetworkRequest(QUrl("https://api.bitmart.com/ticker/BMX_ETH")); QNetworkReply* reply = m_manager.get(request); // connect to signal when its done using lambda) QObject::connect(reply, &QNetworkReply::finished, [reply]() { // read data QString ReplyText = reply->readAll(); // qDebug() << ReplyText; // ask doc to parse it QJsonDocument doc = QJsonDocument::fromJson(ReplyText.toUtf8()); // we know first element in file is object, to try to ask for such QJsonObject obj = doc.object(); // ask object for value QJsonValue value = obj.value(QString("bid_1")); qDebug() << "Bid value is" << value.toString();; reply->deleteLater(); // make sure to clean up }); return a.exec(); }

and it outputs
Bid value is "0.000290"

@raven-worx Yes, this is the code. I also did separate new code QNAM()->PUT(request,QFile*) & QNAM()->POST(request,QFile*) on my QT 5.4.1 setup. Everytime after executing the request application memory goes on increasing till it is equivalent to given file size(here I used 1GB file & memory increased by 1GB).

@praveen0991kr
damn...thats the drawback of using QNetworkAccessManager with a plain tcp socket.

Your response also has to be a HTTP response in order to make QNetworkReply work properly.

E.g.

HTTP/1.0 200 OK Date: Fri, 01 Jan 1970 23:59:59 GMT Content-Type: text/html Content-Length: 1259 <CONTENT-with-a-size-of-1259-bytes>

So the most important is the first line that says everything was ok. Which is reflected by QNetworkReply's error.
I would take this as an minimal example for an response, don't know for sure which headers are mandatory.
Note the empty line between the header and body section! And each line should end with \r\n
See RFC-2616 for more details.

@d1.psy
so you want the cookies from the requests you already made with QtWebEngine?
If so take a look at QWebEngineCookieStore (see it's signals) and "sync" the cookies into your QNAM.

resolved !!
i've chenged

m_pNetworkAccessManager->get(request);

by

request.setRawHeader("Content-Type", "application/x-www-form-urlencoded"); QByteArray par=""; m_pNetworkAccessManager->post(request,par);

sure i will reply with the project code

QNetworkRequest req(url);
reply=qnam.get(req);
QObject::connect(reply,SIGNAL(finished()),this,SLOT(slotFinished()));

@ksranjith786 said:

Could you please provide guidelines or code snippet to use QNetworkAccessManager using multi threaded env.

No, I can't, sorry.
Not that I don't want to, but I don't know of any way you can control the number of threads QNetworkAccessManager uses internally (I think it's hardcoded). If I were to do multithreading with NAM I'd do it like you - thread the reply's processing. Unfortunately this bears no weight on the HTTP response time.

On a related note, I would always prefer to use TCP/IP directly, as it provides much more fine-grained control of what's happening (including threading). The downside of that approach however, is that it'd require implementing the HTTP protocol by hand.

Perhaps, as @p3c0 suggested, you could try to ask the question on the mailing list were you might get responses from the actual developers of the module.

Kind regards.

@djee In My Way connectToHost To Http Server Not Working, So I Call QSslConfiguration::defaultConfiguration(); Instead.

Hi and welcome to devnet,

That's because you are calling exec on _eventLoop twice. You should rather use a local QEventLoop or not allow the query to start if already in progress.

@SGaist Hi, I resolved the issue. I was actually firing sendCustomRequest() api as I was using a specific url query in request which was needed in to fire via HEAD method. Before firing sendCustomRequest() api I was also creating & resetting my ssl configuration. So, instead I directly now use the head() api to fire my HEAD request. Now,finished signal by reply gets fired instantaneously & I am able to read my specific header value in response in no time.

Thanks for your time..!! :)

You're welcome !

Since you have it working now, please update the thread title prepending [solved] so other forums users may know a solution has been found :)

Hi, this post might help you, basically it says you should check you've copied also the Qt4Core.dll, Qt4Gui.dll etc. to your bin directory.