QNetworkAccessManager does not signal finished

[lukas.zachy]

Hello all,
I begin to play with Qt and got stuck with QNetworkAccessManager.
I can not find any difference to the provided example (googlesuggest), but the example works and my code does not

It seems that the network manager doesn't emit finished signal.

The project consists of two classes, one is GUI, second should should access web.

debugging output is:

Starting D:\documents\programming\slovnik-prekladac-qt\Dict-build-desktop\debug\Dict.exe...
translateText called 
translateText ends 
D:\documents\programming\slovnik-prekladac-qt\Dict-build-desktop\debug\Dict.exe exited with code 0

Starting D:\documents\programming\slovnik-prekladac-qt\Dict-build-desktop\debug\Dict.exe...
translateText called 
translateText ends 
D:\documents\programming\slovnik-prekladac-qt\Dict-build-desktop\debug\Dict.exe exited with code 0

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header:

#ifndef TRANSLATE_H
#define TRANSLATE_H
#include <QString>
#include <QtNetwork>
class Translate :public QObject
{
    Q_OBJECT
public:
    Translate();
    void translateText(QString which);
public slots:
    void dataRcd(QNetworkReply *nt);
signals:
    void textTranslated(QString *result);
 
private:
    QNetworkAccessManager netmanager;
};
#endif // TRANSLATE_H

#ifndef TRANSLATE_H
#define TRANSLATE_H
#include <QString>
#include <QtNetwork>
class Translate :public QObject
{
    Q_OBJECT
public:
    Translate();
    void translateText(QString which);
public slots:
    void dataRcd(QNetworkReply *nt);
signals:
    void textTranslated(QString *result);

private:
    QNetworkAccessManager netmanager;
};
#endif // TRANSLATE_H

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code:

#include "translate.h"
#include <QtDebug>
Translate::Translate()
{
  QObject::connect(&netmanager,SIGNAL(finished(QNetworkReply*)),this,SLOT(dataRcd(QNetworkReply*)));
}
 
void Translate::dataRcd(QNetworkReply *nt){
    qDebug()<<"dataRcd called";
    emit textTranslated(new QString ("slot dataRcd called"));
}
 
void Translate::translateText(QString which){
    qDebug() <<"translateText called";
    emit textTranslated(new QString("pre network manager"));
    QNetworkRequest req(QUrl("http://www.google.com"));
    netmanager.get(req);
    qDebug()<<"translateText ends";
}

#include "translate.h"
#include <QtDebug>
Translate::Translate()
{
  QObject::connect(&netmanager,SIGNAL(finished(QNetworkReply*)),this,SLOT(dataRcd(QNetworkReply*)));
}

void Translate::dataRcd(QNetworkReply *nt){
    qDebug()<<"dataRcd called";
    emit textTranslated(new QString ("slot dataRcd called"));
}

void Translate::translateText(QString which){
    qDebug() <<"translateText called";
    emit textTranslated(new QString("pre network manager"));
    QNetworkRequest req(QUrl("http://www.google.com"));
    netmanager.get(req);
    qDebug()<<"translateText ends";
}

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Any advice or hint would be a great help.

Cheers
lukas

[tbscope]

See the network reply error for possible errors.

[lukas.zachy]

not sure if I am doing it right...
I changed it to

void Translate::translateText(QString which){
    qDebug() <<"translateText called";
    emit textTranslated(new QString("pre network manager"));
    QNetworkRequest req(QUrl("http://www.google.com"));
    QNetworkReply *rpl = netmanager.get(req);
    qDebug()<<rpl->errorString();
    qDebug()<<rpl->error();
    qDebug()<<"translateText ends";
}

void Translate::translateText(QString which){
    qDebug() <<"translateText called";
    emit textTranslated(new QString("pre network manager"));
    QNetworkRequest req(QUrl("http://www.google.com"));
    QNetworkReply *rpl = netmanager.get(req);
    qDebug()<<rpl->errorString();
    qDebug()<<rpl->error();
    qDebug()<<"translateText ends";
}

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output is now

translateText called 
"Unknown error" 
0 
translateText ends

translateText called 
"Unknown error" 
0 
translateText ends

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[merajc]

Hello. Apologies for posting on such an old thread, I'm new to the forum.

I've got the same exact problem, and I just can't figure out the solution. Has anyone got tips? Should I post my project here?

Thank you

[ChrisW67]

The example in the zip file does not compile as-is. However, the problem appears to be that the Translate object is stack allocated and goes out of scope and is destroyed before a reply can be received.

If you still cannot see the problem then post a compilable example that shows what you think is broken.

[merajc]

Thanks for the reply, that was exactly the problem.

I made the object heap-allocated and it did not work. I then simply added a destructor and it worked.