Compound Document Interfaces

The following tables list the interfaces implemented by OLE containers, OLE servers, and compound document objects. The required interfaces must be implemented on the components for which they are listed. For example, containers must implement the IOleClientSite and IAdviseSink interfaces. All other features are optional. If you want to include a particular feature in your application, however, you must implement the interfaces shown for that feature in the table below. All other interfaces are required only if you are including a particular feature. For example, if you want your application to do message filtering (recommended), you must implement IMessageFilter.

The following table lists required and optional behaviors for OLE containers and which interfaces you must implement for each.

OLE Containers

Behavior	Interfaces
Required Behaviors	IOleClientSite
	IAdviseSink
Message Filtering	IMessageFilter
Linking	none
Linking to Embedded Objects	IOleItemContainer
	IPersistFile
	IClassFactory
In-Place Activation	IOleInPlaceSite
	IOleInPlaceActive-Frame
	IOleInPlaceUIObject
Drag and Drop	IDropSource
	IDropTarget
	IDataObject

The following table lists required and optional behaviors for OLE servers and their compound document objects and which interfaces you must implement for each. The table distinguishes OLE servers and their objects in order to clarify which component implements which interfaces. The table also notes the different requirements of objects provided by out-of-process versus in-process servers.

Feature	OLE Server	Compound Document Object
		Out-of-Process	In-Process
Required Behaviors	IClassFactory	IOleObject	IOleObject
		IDataObject	IDataObject
		IPersistStorage	IPersistStorage
			IViewObject2
			IOleCache2
Message Filtering	IMessageFilter
Linking	IOleItemContainer		IOleLink
	IPersistFile		IExternalConnection
In-Place- Activation		IOleInPlaceObject	IOleInPlaceObject
		IOleInPlace- ActiveObject	IOleInPlaceActive- Object
Drag and Drop	IDropSource
	IDropTarget
	IDataObject