IViewObject2

The IViewObject2 interface is an extension to the IViewObject interface which returns the size of the drawing for a given view of an object. You can prevent the object from being run if it isn’t already running by calling this method instead of IOleObject::GetExtent.

Like the IViewObject interface, IViewObject2 cannot be marshaled to another process. This is because device contexts are only effective in the context of one process.

The OLE-provided default implementation provides the size of the object in the cache.

When to Implement

Object handlers and in-process servers that manage their own presentations implement IViewObject2 for use by compound document containers.

When to Use

A container application or object handler calls the GetExtent method in the IViewObject2 interface to get the object’s size from its cache.

Methods in Vtable Order

IUnknown Methods	Description
QueryInterface	Returns pointers to supported interfaces.
AddRef	Increments reference count.
Release	Decrements reference count.

IViewObject Methods	Description
Draw	Draws a representation of the object onto a device context.
GetColorSet	Returns the logical palette the object uses for drawing.
Freeze	Freezes the drawn representation of an object so it will not change until a subsequent Unfreeze.
Unfreeze	Unfreezes the drawn representation of an object.
SetAdvise	Sets up a connection between the view object and an advise sink so that the advise sink can receive notifications of changes in the view object.
GetAdvise	Returns the information on the most recent SetAdvise.

IViewObject2 Method	Description
GetExtent	Returns the size of the view object from the cache.