<DefaultEvent("CollectionChanged")> _ 
Public Class MyCollection
    Inherits BaseCollection

    Public Event CollectionChanged (ByVal sender As Object, _
        ByVal e As CollectionChangeEventArgs)

    ' Insert additional code.
End Class 'MyCollection

[DefaultEvent("CollectionChanged")]
public class MyCollection : BaseCollection {

    private CollectionChangeEventHandler onCollectionChanged;

    public event CollectionChangeEventHandler CollectionChanged {
       add {
          onCollectionChanged += value;
       }
       remove {
          onCollectionChanged -= value;
       }
    }
    // Insert additional code.
}

[DefaultEvent("CollectionChanged")]
public ref class TestCollection: public BaseCollection
{
private:
    CollectionChangeEventHandler^ onCollectionChanged;

public:
    event CollectionChangeEventHandler^ CollectionChanged 
    {
    public:
        void add(CollectionChangeEventHandler^ eventHandler)
        { 
            onCollectionChanged += eventHandler; 
        }

    protected:
        void remove(CollectionChangeEventHandler^ eventHandler) 
        { 
            onCollectionChanged -= eventHandler; 
        }
    }
    // Insert additional code.
};

Public Shared Function Main() As Integer
    ' Creates a new collection.
    Dim myNewCollection As New MyCollection()

    ' Gets the attributes for the collection.
    Dim attributes As AttributeCollection = TypeDescriptor.GetAttributes(myNewCollection)

    ' Prints the name of the default event by retrieving the
    ' DefaultEventAttribute from the AttributeCollection. 
    Dim myAttribute As DefaultEventAttribute = _
        CType(attributes(GetType(DefaultEventAttribute)), DefaultEventAttribute)
    Console.WriteLine(("The default event is: " & myAttribute.Name))
    Return 0
End Function 'Main

public static int Main() {
    // Creates a new collection.
    MyCollection myNewCollection = new MyCollection();

    // Gets the attributes for the collection.
    AttributeCollection attributes = TypeDescriptor.GetAttributes(myNewCollection);

    /* Prints the name of the default event by retrieving the 
     * DefaultEventAttribute from the AttributeCollection. */
    DefaultEventAttribute myAttribute = 
       (DefaultEventAttribute)attributes[typeof(DefaultEventAttribute)];
    Console.WriteLine("The default event is: " + myAttribute.Name);
    return 0;
 }

int main()
{
    // Creates a new collection.
    DefaultEventAttributeExample::TestCollection^ newCollection = 
        gcnew DefaultEventAttributeExample::TestCollection;

    // Gets the attributes for the collection.
    AttributeCollection^ attributes = 
        TypeDescriptor::GetAttributes(newCollection);

    // Prints the name of the default event by retrieving the 
    // DefaultEventAttribute from the AttributeCollection.
    DefaultEventAttribute^ attribute = (DefaultEventAttribute^)
        attributes[DefaultEventAttribute::typeid];
    Console::WriteLine("The default event is: {0}", attribute->Name);
}