Looping through QNetworkAccessManager get() routines, retrieve order on finish

Question

I have a QNetworkAccessManager as a member of my class. I connect the finished signal from this manager to the replyFinished function I have written.

manager = new QNetworkAccessManager(this);
    connect(manager, SIGNAL(finished(QNetworkReply*)),this,SLOT(replyFinished(QNetworkReply*)));

In a separate routine, I loop through a get call from the manager

for (int si = 0; si<numLines; si++)
{
    QString line = lines[si];
    manager->get(QNetworkRequest(QUrl(line)));
}

In my replyFinished slot routine, I know I may not receive the signals in the order they were performed in the loop, but is there any way I can obtain that information? That is, is there a clever way I can obtain "si" in my replyFinished routine? Thanks for the help!

Answer 1

QNetworkAccessManager::get() returns a pointer to the QNetworkReply object. This pointer is the same one that is passed your replyFinished() slot. You can use a QMap to store pairings of QNetworkReply* pointers and integers (si in your code).

Here is a working example;

#include <QCoreApplication>
#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QUrl>
#include <QMap>

#include <QtDebug>

QNetworkAccessManager am;
void finished(QNetworkReply* reply);

QMap<QNetworkReply*, int> requests;

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QObject::connect(&am, &QNetworkAccessManager::finished, finished);

    QStringList links;
    links << "http://google.com";
    links << "http://taobao.com";
    links << "http://stackoverflow.com";
    links << "http://stackexchange.com";
    links << "http://bing.com";


    for (int i=0; i < links.size(); i++)
    {
        requests.insert(am.get(QNetworkRequest(QUrl(links[i]))), i);
    }

    return a.exec();
}

void finished(QNetworkReply* reply)
{
    qDebug() << requests[reply];
}