BindableCollection - canton7/Stylet GitHub Wiki
Overview
BindableCollection<T> is a subclass of ObservableCollection<T>. It's the class to use if you have a collection of something in your ViewModel, and want to use it as the ItemsSource / etc for something in your View (and have the View be notified whenever an item is added to / removed from that collection).
However, it adds a couple of useful extra features:
- New
AddRange,RemoveRange, andRefreshmethods - Is thread-safe
New Methods
ObservableCollection<T> is missing a couple of very useful methods: AddRange and RemoveRange.
These do pretty much what you'd expect, allowing you to add a remove a range of elements at once, without
having to manually iterate over each element and calling collection.Add(element) on each (while raising lots
of events for each element added). AddRange and RemoveRange will raise one set of events per range added/removed only.
Refresh is a convenience.
It does not modify the collection in any way, but does cause the PropertyChanged and CollectionChanged events to be fired, indicating to any UI elements that the collection has been modified and that they should reload their data.
It's not often needed, but when it is it's really needed.
Thread Safety
Thread safety is achieved by dispatching all actions (adds, removes, clear, reset, etc) to the UI thread. The dispatch uses Execute.OnUIThreadSync, which means that:
- These operations are synchronous: the method being called won't return until the action has been completed.
- They're free if you're already on the UI Thread - the operation will be carried out synchronously in this case.
- All
PropertyChangedandCollectionChangedevents are always raised on the UI thread.
That last point means that there is no PropertyChangedDispatcher property on BindableCollection<T>, as there is with PropertyChangedBase - the event is always raised on the UI thread, since the operation the property relates to is always performed on the UI thread. Similarly, there's no CollectionChangedDispatcher concept.