OleCreate

This function creates an embedded object identified by a CLSID. It is typically used to implement a menu item that allows the end user to insert a new object.

At a Glance

Syntax

WINOLEAPI OleCreate( REFCLSID rclsid, REFIID riid,
DWORD renderopt, FORMATETC * pFormatEtc,
IOleClientSite * pClientSite, IStorage * pStg, void ** ppvObject);

Parameters

rclsid

[in] CLSID of the embedded object that is to be created.

riid

[in] Reference to the identifier of the interface, usually IID_IOleObject (defined in the OLE headers as the interface identifier for IOleObject), through which the caller will communicate with the new object.

renderopt

[in] Value from the enumeration OLERENDER, indicating the locally cached drawing capabilities the newly created object is to have. The OLERENDER value chosen affects the possible values for the pFormatEtc parameter.

pFormatEtc

[in] Depending on which of the OLERENDER flags is used as the value of renderopt, pointer to one of the FORMATETC enumeration values. Refer to the OLERENDER enumeration for restrictions. This parameter, along with the renderopt parameter, specifies what the new object can cache initially.

pClientSite

[in] If you want OleCreate to call IOleObject::SetClientSite, pClientSite is the pointer to the IOleClientSite interface on the container. The value can be NULL, in which case you must specifically call IOleClientSite::SetClientSite before attempting operations.

pStg

[in] Pointer to an instance of the IStorage interface on the storage object. This parameter cannot be NULL.

ppvObject

[out] Pointer to the pointer variable that receives the interface pointer requested in riid. Upon successful return, *ppvObject contains the requested interface pointer.

Return Values

This function supports the standard return value E_OUTOFMEMORY, as well as the following:

Remarks

Passing into this function any invalid and, under some circumstances, NULL pointers will result in unexpected termination of the application.

The OleCreate function creates a new embedded object, and is typically called to implement the menu item Insert New Object. When OleCreate returns, the object it has created is blank (contains no data), unless renderopt is OLERENDER_DRAW or OLERENDER_FORMAT, and is loaded. Containers typically then call the OleRun function or IOleObject::DoVerb to show the object for initial editing.

The rclsid parameter specifies the CLSID of the requested object. CLSIDs of registered objects are stored in the system registry. When an application user selects Insert Object, a selection box allows the user to select the type of object desired from those in the registry. When OleCreate is used to implement the Insert Object menu item, the CLSID associated with the selected item is assigned to the rclsid parameter of OleCreate.

The riid parameter specifies the interface the client will use to communicate with the new object. Upon successful return, the ppvObject parameter holds a pointer to the requested interface.

The created object's cache contains information that allows a presentation of a contained object when the container is opened. Information about what should be cached is passed in the renderopt and pFormatetc values. When OleCreate returns, the created object's cache is not necessarily filled. Instead, the cache is filled the first time the object enters the running state. The caller can add additional cache control with a call to IOleCache::Cache after the return of OleCreate and before the object is run. If renderopt is OLERENDER_DRAW or OLERENDER_FORMAT, OleCreate requires that the object support the IOleCache interface. There is no such requirement for any other value of renderopt.

If pClientSite is non-NULL, OleCreate calls IOleObject::SetClientSite through the pClientSite pointer. IOleClientSite is the primary interface by which an object requests services from its container. If pClientSite is NULL, you must make a specific call to IOleObject::SetClientSite before attempting any operations.