This is Xamarin's bug tracking system. For product support, please use the support links listed in your Xamarin Account.
Bug 8366 - BindingList<T> is not raising ItemChanged event if Item implements INotifyPropertyChanged
: BindingList<T> is not raising ItemChanged event if Item implements INotifyPro...
Product: iOS
Classification: Xamarin
Component: Class Libraries
: 6.0.x
: PC Mac OS
: --- normal
: Untriaged
Assigned To: Sebastien Pouliot
  Show dependency treegraph
Reported: 2012-11-13 07:33 EST by Michal
Modified: 2012-11-14 11:33 EST (History)
4 users (show)

See Also:
Test Case URL:
External Submit: ---


Description Michal 2012-11-13 07:33:56 EST
Current implementation of BindingList<T> is not complete. It is not raising
ListChangedType.ItemChanged event for items implementing INotifyPropertyChanged
interface when some property of such item changes.
Comment 1 Sebastien Pouliot 2012-11-13 16:08:17 EST
Mono's unit tests for BindingList<T> works correctly. Could you provide us a
test case to duplicate the issue you're seeing ? Thanks!
Comment 2 Michal 2012-11-14 03:57:27 EST
And are Mono's unit tests complete? They are working correctly does not mean
they are covering everything :)

Try this:
        private class Item : INotifyPropertyChanged
            public event PropertyChangedEventHandler PropertyChanged;

            private string _name;
            public string Name
                get { return _name; }
                    if (_name != value)
                        _name = value;

            private void OnPropertyChanged(string name)
                var fn = this.PropertyChanged;
                if (fn != null)
                    var args = new PropertyChangedEventArgs(name);
                    fn(this, args);

        private void TestBindingList()
            var list = new BindingListEx<Item>();
            list.ListChanged += (object sender, ListChangedEventArgs e) => 

            var item = new Item() { Name = "1" };

            item.Name = "2";

Call TestBindingList method. Current output is ItemAdded, but it should be two
lines: ItemAdded and then also ItemChanged.

MonoTouch 6.0.6 which is the latest stable version MonoDevelop is offerring us.
Comment 3 Sebastien Pouliot 2012-11-14 08:11:37 EST
> And are Mono's unit tests complete?

Unlikely. Still even if it was 100% covered by unit tests it would not mean
it's bug free either.

OTOH providing a test case to us makes sure you'll get a fix for *your* bug,
not a similar one we could find while hunting for it (which would require you
to re-open the bug on the next MT release). Also we can turn provided test
cases into new unit tests to ensure the feature does not regress in the future.
Comment 4 Michal 2012-11-14 08:19:52 EST
I understand and thank you
Comment 5 Sebastien Pouliot 2012-11-14 09:07:39 EST
It looks like mono/master already has the fix for this. I'll backport (to
2-10/monotouch) and test this.
Comment 6 Sebastien Pouliot 2012-11-14 11:33:16 EST
Fixed in:
ios6: d5e0fa42b97388903d7ac99437aa5d509b9e1444
master: 3c402b9f9d4fb99cd920190f1992bb45083cd8a6

Test added:
mono/master: 0dd29ed7219f6c943cc9c979b83eb5c0b874d6e0
mono-2-10: a214478534f8d261cdcbec33f0d9107b39038945
mobile-master: f41893591b3dda508d52b1831ac6f5eae4556499

Note You need to log in before you can comment on or make changes to this bug.