Page with ListView throws ArgumentException (on WinPhone only)

BruceWilkins

A page with a ListView/ ObservableCollection is throwing an ArugumentException, only on Windows Phone and only when navigating back up the stack to the page.

The exception originates as

A first chance exception of type 'System.ArgumentException' occurred in System.Windows.ni.dll

then is thrown as an unhandled exception in App.Application_UnhandledException.

It looks like this is only a problem when populating the ObservableCollection asyncronously using async/ await in OnAppearing, although the result is dispatched to the UI thread using Device.BeginInvokeOnMainThread().

Any ideas?

FredyWenger

@BruceWilkins:
I have similar problems with a ListView (but with List as Items-Source) on a PopUp (only in WP).
The app crashes by the second call...
I have mentioned that and hope, that It will be solved in the next release...

BruceWilkins

Been investigating some work arounds but its looking to be a show stopper for us, unfortunately.

I've tested with the latest pre release versions but it looks like the same issue is there.

Can someone from Xamarin.Forms comment? Is this a known issue?

FredyWenger

@BruceWilkins:

I (hopefully) have good news...
I had commented an already filled bug in Bugzilla.
Today the state was changed to "Confirmed" and "In progress".
Link:
https://bugzilla.xamarin.com/show_bug.cgi?id=29229

So let's hope that this is "our Bug", that it will be solved and that the next update will be released in not time

BruceWilkins

Great, I'll add our exception info incase it helps in resolving the issue.

Thanks for the heads up!

BruceWilkins

May be a separate issue, yours is System.NullReferenceException, ours is System.ArgumentException.

I've added a new issue in Bugzilla:

Bug 30397 - Page with ListView on WinPhone throws ArgumentException when navigating back

FredyWenger

@BruceWilkins:
FYI:
I have received a mail from Bugzilla, that the bug is solved (and the solve is released in the next version):
https://bugzilla.xamarin.com/show_bug.cgi?id=29229

that - according Miguel - should be released in the next 2-3 weeks.

See his comment here: forums.xamarin.com/discussion/41588/how-to-make-forms-stable#latest

BruceWilkins

Looks like ours is a separate issue:

Bug 30397 - Page with ListView on WinPhone throws ArgumentException when navigating back

BruceWilkins

Incase anyone else runs into this issue- it appears to be related to clearing the lists observable collection in OnDisappearing()