Public Class ReadOnlyObservableCollection(Of T) _
    Inherits ReadOnlyCollection(Of T) _
    Implements INotifyCollectionChanged, INotifyPropertyChanged

Dim instance As ReadOnlyObservableCollection(Of T)

public class ReadOnlyObservableCollection<T> : ReadOnlyCollection<T>, 
    INotifyCollectionChanged, INotifyPropertyChanged

generic<typename T>
public ref class ReadOnlyObservableCollection : public ReadOnlyCollection<T>, 
    INotifyCollectionChanged, INotifyPropertyChanged

JScript does not support generic types or methods.

You cannot directly create an instance of this class in XAML.