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c#.netwpfobservablecollectionwpf-4.0

Difference between ObservableCollection and BindingList


I want to know the difference between ObservableCollection and BindingList because I've used both to notify for any add/delete change in Source, but I actually do not know when to prefer one over the other.

Why would I choose one of the following over the other?

ObservableCollection<Employee> lstEmp = new ObservableCollection<Employee>();

or

BindingList<Employee> lstEmp = new BindingList<Employee>();

Solution

  • An ObservableCollection can be updated from UI exactly like any collection. The true difference is rather straightforward:

    ObservableCollection<T> implements INotifyCollectionChanged which provides notification when the collection is changed (you guessed ^^) It allows the binding engine to update the UI when the ObservableCollection is updated.

    However, BindingList<T> implements IBindingList.

    IBindingList provides notification on collection changes, but not only that. It provides a whole bunch of functionality which can be used by the UI to provide a lot more things than only UI updates according to changes, like:

    • Sorting
    • Searching
    • Add through factory (AddNew member function).
    • Readonly list (CanEdit property)

    All these functionalities are not available in ObservableCollection<T>

    Another difference is that BindingList relays item change notifications when its items implement INotifyPropertyChanged. If an item raises a PropertyChanged event, the BindingList will receive it an raises a ListChangedEvent with ListChangedType.ItemChanged and OldIndex=NewIndex (if an item was replaced, OldIndex=-1). ObservableCollection doesn't relay item notifications.

    Note that in Silverlight, BindingList is not available as an option: You can however use ObservableCollections and ICollectionView (and IPagedCollectionView if I remember well).