SuperImage - PlaceHolder images not shown

Dec 5, 2013 at 12:16 AM
Edited Dec 5, 2013 at 12:31 AM
I'm on a wp8 app using a LongListSelector. The datatemplate of the items in the LLS uses the SuperImage with a PlaceHolderImage.

Now my scenario:

LoadData(), but this get's called several times to load data in chunks, with each chunk I'm adding the items to an Sorted Observable collection ( with Deployment.Current.Dispatcher.BeginInvoke ).
SortedObservable code here: http://www.xamlplayground.org/post/2010/04/27/Keeping-an-ObservableCollection-sorted-with-a-method-override.aspx
But because of the fact that the items are sorted, I need to reposition the LLS to top after the collection has changed! This is done through extending the LLS.
with this: http://developer.nokia.com/Community/Wiki/Fixing_the_LongListSelector ( only the CollectionChanged event handler )
With all this in place, the last time the LLS is put on top, I'm getting empty images! Instead of the PlaceHolderImages.

When you then scroll through the list to the bottom and back up again, the placeholder images are all of a sudden visible.

Any thoughts? I can only send the complete project if needed, bit to much code to make a repo :(

Another observation, when I position the list to the top and do a normal refresh, while the items are being loaded you'll see the placeholderimage AND the real image ( cached after first load ) together! When all items are loaded the placeholder images are collapsed! But to many are collapsed... and the correct ones reappear after scrolling!

I've uploaded a video with demo, take not of the item called "Lunches Culturels"
http://youtu.be/B62ZUCzho34
Coordinator
Dec 5, 2013 at 7:01 PM
I need a repro with steps, 1 ticket per issue please.
Dec 5, 2013 at 8:19 PM
Ok... I'll try to get this seperated in a test project
Coordinator
Dec 5, 2013 at 8:59 PM
I'm seeing two things you're raising here, placeholder image issues + image collapsed. do you feel they the same issue or separate issues?
Dec 5, 2013 at 9:45 PM
I'm guessing they are one and the same because I'm thinking it's a UI threading issue... but I'm unsure.

Most visible problem would be the end result: missing place holder items until you scroll.