QNetworkAccessManager Download Image

elveatles

Hi, I'm using PySide and I'm having trouble figuring out why I can't download an image properly using QNetworkAccessManager.
Here's what I'm doing:

manager = QNetworkAccessManager()

def downloadThumbnail(self):
    thumbnail = 'https://.../some-thumbnail.jpg'
    request = QNetworkRequest(QUrl(thumbnail)) 
    reply = manager.get(request)
    reply.finished.connect(self.onThumbnailLoaded)

@Slot()
def onThumbnailLoaded(self):
    if reply.error() == QNetworkReply.NoError:
        thumbnailData = reply.readAll()
        pixmap = QPixmap()
        pixmap.loadFromData(thumbnailData)
        self.someLabel.setPixmap(pixmap)

There is no reply error. reply.readAll() does not have an error. pixmap.loadFromData returns False, but I don't know why.

jsulm

I would check what reply.readAll() returns. You can even store it in a file and check that file.

elveatles

I updated the code to be:

thumbnailData = reply.readAll()
tempFile = QFile(r'C:\temp.jpg')
tempFile.open(QIODevice.WriteOnly)
tempFile.write(thumbnailData)
tempFile.close()

When I open the file, it says: "Windows Photo Viewer can't open this picture because the file appears to be damaged, corrupted, or is too large."

But if I open the url in a browser I can see the image. If I do thumbnailData.count(), I get 304, so there is something there. I don't know what I'm doing wrong.

jsulm

What is the content of thumbnailData after reading the reply?

elveatles

Printing out thumbnailData.data(), I get:

302 Found

The resource was found at https://...

So I realize my problem now. The thumbnail url is redirecting me to another url which is what I actually want to use to download for the QPixmap.

Thanks for your help everyone.