[solved] get and save Image from URL is not working

Abin

I have two list of images to be downloaded from network. I use qnetworkaccessmanager to get image from url. But on the reply slot there is no image data with the reply. :( I am not able to figure out where am I going wrong.. If someone is able to figure out, pl reply...

@ void SyncDialog::getImages()
{
qDebug() << Q_FUNC_INFO << "Invoked";

int groupMasterCount = mSyncMasterData.groupMasterList.count();
qDebug() << Q_FUNC_INFO << "groupmastercout" << groupMasterCount;

for (int i = 0 ; i < groupMasterCount; ++i)
{
    GroupMaster groupItem = mSyncMasterData.groupMasterList.at(i);
    QNetworkReply *reply =
            mImageGetNwMgr.get(QNetworkRequest(QUrl(groupItem.image)));
    reply->setProperty("name", QVariant("G_" + groupItem.groupCode));

    connect(reply, SIGNAL(readyRead()), this, SLOT(saveImage()));

    qDebug() << Q_FUNC_INFO << "get call reply" << reply->readAll();
    qDebug() << Q_FUNC_INFO << "get url" << groupItem.image;

    mSyncMasterData.groupMasterList[i].image.clear();
#ifdef Q_OS_WIN
    mSyncMasterData.groupMasterList[i].image = "C:/POS/Images/G_"
                                                    +groupItem.groupCode;
#else
    mSyncMasterData.groupMasterList[i].image = "/mnt/sdcard/POS/Images/G_"
                                                    +groupItem.groupCode;
#endif

}

int itemMasterCount = mSyncMasterData.itemMasterList.count();
qDebug() << Q_FUNC_INFO << "itemmastercout" << itemMasterCount;

for (int i = 0 ; i < itemMasterCount; ++i)
{
    ItemMaster item = mSyncMasterData.itemMasterList.at(i);
    QNetworkReply *reply =
            mImageGetNwMgr.get(QNetworkRequest(QUrl(item.imagePath)));
    reply->setProperty("name", QVariant("I_" + item.itemCode));

    connect(reply, SIGNAL(readyRead()), this, SLOT(saveImage()));

    qDebug() << Q_FUNC_INFO << "get call reply" << reply->readAll();
    qDebug() << Q_FUNC_INFO << "get url" << item.imagePath;

    mSyncMasterData.itemMasterList[i].imagePath.clear();
#ifdef Q_OS_WIN
    mSyncMasterData.itemMasterList[i].imagePath = "C:/POS/Images/I_"
                                                    +item.itemCode;
#else
    mSyncMasterData.itemMasterList[i].imagePath = "/mnt/sdcard/POS/Images/G_"
                                                    +item.itemCode;
#endif

}

qDebug() << Q_FUNC_INFO << "Exits";
}

@
In my slot I save images , but in reply->readAll gives me ""

@void SyncDialog::saveImage()
{
qDebug() << Q_FUNC_INFO << "Invoked";

QObject *senderObj = sender();
QNetworkReply *reply = qobject_cast<QNetworkReply*>(senderObj);

QImage* img2 = new QImage();
img2->loadFromData(reply->readAll());
qDebug() << Q_FUNC_INFO << "image nw reply" << reply->readAll();
QString imageName = reply->property("name").toString();
qDebug() << Q_FUNC_INFO << "imageName" << imageName;

if(img2->isNull())
{
    qDebug() << Q_FUNC_INFO << "image is null";
    return;
}

#ifdef Q_OS_WIN
img2->save("C:/POS/Images/" + imageName);
#else
img2->save("/mnt/sdcard/POS/Images/" + imageName);
#endif

qDebug() << Q_FUNC_INFO << "Exits";
}@

Also I see in logs "libpng error: Read Error" and the slot is invoked multiple times...

dheerendra

Is the image url correct ? Is the slot called ? Is it network url ? Are able to access this URL from browser ?

Abin

Thanks all,

I resolved the issue with few changes :)

@connect(reply, SIGNAL(finished()), this, SLOT(saveImage()));@

finished() makes sure complete image data is received from n/w.

@QByteArray      imageData   = reply->readAll();
QImage          *image      = new QImage();

image->loadFromData(imageData);

@
reply->readAll() should be saved as first call clears the data after returning it.

@ image->save("C:/POS/Images/" + imageName + ".png"@

don't forget to specify image format (either in filename or as parameter)