Can there be any performance benefit by implementing IList<T> with INotifyCollectionChanged

Emon Haque 3,176

I've never implemented INotifyCollectionChanged before tonight and didn't event think about doing so. Here's how I did and in my case I only needed Add and Remove so I left all other unimplemented. For fair evaluation, I've created PDF document of 1133 pages several times with both ObservableCollection<T> and TestList<T>. With ObservableCollection<T> it takes about 302 seconds on average and with TestList<T>, 305 seconds.

Do programmers implement IList<T> with INotifyCollectionChanged for performance benefit or just to have a container with reduced functionality?

Peter Fleischer (former MVP) 19,306 Reputation points

2020-10-12T05:00:50.677+00:00

Hi,
IList <T> is an old development of the ArrayList as a typed collection without the possibility of informing about changes (adding, deleting elements). The newer ObservableCollection<T> can inform about changes (via NotifyCollectionChanged). In most cases I need this Possibility for refreshing UI.
Emon Haque 3,176 Reputation points

2020-10-12T13:20:13.563+00:00

anonymous user-3316 , Yes of course in WPF. In terms of performance I'll always have better performance with ObservableCollection<T> than subclass of something that implements INotifyCollectionChanged, right?
Andy ONeill 361 Reputation points

2020-10-12T17:21:29.593+00:00

Programmers just use observablecollection<t> in my experience.
I would suggest reducing the amount of data in a collection using filtering or paging rather than re inventing observablecollection.
Emon Haque 3,176 Reputation points

2020-10-12T19:34:25.003+00:00

@Andy ONeill , I've replaced almost all ObservableCollection<T> with ICollectionView in ViewModels of one of my applications I use. In one place I've one static ObservableCollection per Type and in ViewModels only ICollectionView.

Whenever I need to filter on selection change, I call Refresh() and where I need filter but there's no chance of selection change, I've LiveFilter. This literally has obliterated all the events and subscriptions I'd in my ViewModels to filter objects, enjoying it a lot and also deleted all properties for SelectedItem binding and using SelectedValuePath and SelectedValue instead.

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Can there be any performance benefit by implementing IList<T> with INotifyCollectionChanged