The IUICollectionChangedEvent interface is implemented by the application and defines the method required to handle changes to a collection at run time.

public interface IUICollectionChangedEvent

Documentation

[IUICollectionChangedEvent] on MSDN

2: IUICollectionChangedEvent

3: IUISimplePropertySet

Summary

IUISimplePropertySet is a read-only interface that can be implemented by the Windows Ribbon framework and a Ribbon host application, depending on the situation. When implemented by the Ribbon framework, IUISimplePropertySet defines the method for retrieving property key values. In a host application, IUISimplePropertySet is implemented for each item in an item gallery IUICollection object and defines the method for retrieving properties of the selected item.

Enums

4: Constants UI_PKEY_

internal static PropertyKey UI_PKEY_ItemsSource = new PropertyKey(new Guid(Convert.ToString(101, 16).PadLeft(8, '0') + UI_PropertyKey), (int)VarEnum.VT_UNKNOWN); // IEnumUnknown or IUICollection

internal static PropertyKey UI_PKEY_Categories = new PropertyKey(new Guid(Convert.ToString(102, 16).PadLeft(8, '0') + UI_PropertyKey), (int)VarEnum.VT_UNKNOWN); // IEnumUnknown or IUICollection

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