IViewObject::Freeze

Freezes a certain aspect of the object’s presentation so that it does not change until the IViewObject::Unfreeze method is called. The most common use of this method is for banded printing.

HRESULT Freeze(

DWORD dwAspect,	//How the object is to be represented
LONG lindex,	//Part of the object of interest in the draw operation
void * pvAspect,	//Always NULL
DWORD * pdwFreeze	//Points to location containing an identifying key
);

Parameters

dwAspect

[in] Specifies how the object is to be represented. Representations include content, an icon, a thumbnail, or a printed document. Valid values are taken from the enumeration DVASPECT. See the DVASPECT enumeration for more information.

lindex

[in] Portion of the object that is of interest for the draw operation. Its interpretation varies with dwAspect. See the DVASPECT enumeration for more information.

pvAspect

[in] Pointer to additional information about the view of the object specified in dwAspect. Since none of the current aspects support additional information, pvAspect must always be NULL.

pdwFreeze

[out] Pointer to where an identifying DWORD key is returned. This unique key is later used to cancel the freeze by calling IViewObject::Unfreeze. This key is an index that the default cache uses to keep track of which object is frozen.

Return Values

S_OK

The presentation was successfully frozen.

VIEW_S_ALREADYFROZEN

Presentation has already been frozen. The value of pdwFreeze is the identifying key of the already frozen object.

OLE_E_BLANK

Presentation not in cache.

DV_E_LINDEX

Invalid value for lindex; currently; only -1 is supported.

DV_E_DVASPECT

Invalid value for dwAspect.

Remarks

The IViewObject::Freeze method causes the view object to freeze its drawn representation until a subsequent call to IViewObject::Unfreeze releases it. After calling IViewObject::Freeze, successive calls to IViewObject::Draw with the same parameters produce the same picture until IViewObject::Unfreeze is called.

IViewObject::Freeze is not part of the persistent state of the object and does not continue across unloads and reloads of the object.

The most common use of this method is for banded printing.

While in a frozen state, view notifications are not sent. Pending view notifications are deferred to the subsequent call to IViewObject::Unfreeze.

See Also

DVASPECT, IViewObject::Unfreeze