Collection

Today I’d like to present an idea that occurred to me recently. Nothing about WPF this time, this is all about C# class design ! The problem It’s very common in C# programs to have an object that owns a collection of child items with a reference to their parent. For instance, this is the case for Windows Forms controls, which have a collection of child controls (Controls), and a reference to their parent control (Parent).

As you may have noticed, it is not possible to modify the contents of an ObservableCollection on a separate thread if a view is bound to this collection : the CollectionView raises a NotSupportedException : This type of CollectionView does not support changes to its SourceCollection from a thread different from the Dispatcher thread To illustrate this, let’s take a simple example : a ListBox bound to a collection of strings in the ViewModel :