How to Avoid Firing ObservableCollection.CollectionChanged Multiple Times When Replacing All Elements Or Adding a Collection of Elements

Question

I have ObservableCollection collection, and I want to replace all elements with a new collection of elements, I could do:

collection.Cl         


        

Answer 1

You can achieve this by subclassing ObservableCollection and implementing your own ReplaceAll method. The implementation of this methods would replace all the items within the internal Items property, then fire a CollectionChanged event. Likewise, you can add an AddRange method. For an implementation of this, see the answer to this question:

ObservableCollection Doesn't support AddRange method, so I get notified for each item added, besides what about INotifyCollectionChanging?

The difference between Collection.Clear and Collection.ClearItems is that Clear is a public API method, whereas ClearItems is protected, it is an extension point that allows your to extend / modify the behaviour of Clear.