BitmapImage's ImageOpened event not fired in background agent

Question

As in the title, the event is not fired when the code is executed in the BackgroundAgent while it works fine when I execute it in my main app.

Here's my code:

var background = new BitmapImage(new Uri(uri), UriKind.Absolute)){ CreateOptions = BitmapCreateOptions.None };
background.ImageFailed += (s, e) =>
{
    Debug.WriteLine(e);
    // Nothing happens here so I guess that there's no error in the image loading
};
background.ImageOpened += (s, e) =>
{
    Debug.WriteLine("ImageOpened");
    // This line is never printed no the event is never thrown
};

Everthing is running in a Dispatcher thread, and I'm trying to load a remote image (I can't cache it because it's a dynamic image generated by a php page).

Any hint?

EDIT:

Here's the code based on @l3arnon's suggestion:

var backgroundImage = new BitmapImage { CreateOptions = BitmapCreateOptions.None };
backgroundImage.ImageOpened += (s, e) =>
{
                Debug.WriteLine("ImageOpened");
};
backgroundImage.UriSource = new Uri(uri);

still no success though.

Answer 1

My only guess it that it loads the image so fast that you register the event handler too fast. Try first creating the BitmapImage instance and then setting a uri