# IStorage::CreateStorage

Creates and opens a new storage object nested within this storage object.

HRESULT CreateStorage(

const WCHAR * pwcsName, | //Points to the name of the new storage object
DWORD grfMode, | //Access mode for the new storage object
DWORD reserved1, | //Reserved; must be zero
DWORD reserved2, | //Reserved; must be zero
IStorage ** ppstg | //Points to new storage object
); |

Parameters

pwcsName
  [in] Points to a wide character string that contains the name of the newly created storage object. This name can be used later to reopen the storage object.
grfMode
  [in] Specifies the access mode to use when opening the newly created storage object. See the STGM enumeration values for descriptions of the possible values.
reserved1
  [in] Reserved for future use; must be zero.
reserved2
  [in] Reserved for future use; must be zero.
ppstg
  [out] When successful, points to the location of the IStorage pointer to the newly-created storage object. This parameter is set to NULL if an error occurs.

Return Values

S_OK
  The storage object was created successfully.
E_PENDING
  Asynchronous Storage only: Part or all of the necessary data is currently unavailable. For more information see IFillLockBytes and Asynchronous Storage.
STG_E_ACCESSDENIED
  Insufficient permissions to create storage object.
STG_E_FILEALREADYEXISTS
  The name specified for the storage object already exists in the storage object and the grfmode flag includes the flag STGM_FAILIFTHERE.
STG_E_INSUFFICIENTMEMORY
  The storage object was not created due to a lack of memory.
STG_E_INVALIDFLAG
  The value specified for the grfMode flag is not a valid STGM enumeration value.
STG_E_INVALIDFUNCTION
  The specified combination of grfMode flags is not supported.
STG_E_INVALIDNAME
  Invalid value for pwcsName.
STG_E_INVALIDPOINTER
  The pointer specified for the storage object was invalid.
STG_E_INVALIDPARAMETER
  One of the parameters was invalid.
STG_E_REVERTED
  The storage object has been invalidated by a revert operation above it in the transaction tree.
STG_E_TOOMANYOPENFILES
  The storage object was not created because there are too many open files.
STG_S_CONVERTED
  The existing stream with the specified name was replaced with a new storage object containing a single stream called CONTENTS. The new storage object will be added.

Remarks

If a storage with the name specified in the pwcsName parameter already exists within the parent storage object, and the grfMode parameter includes the STGM_CREATE flag, the existing storage is replaced by the new one. If the grfMode parameter includes the STGM_CONVERT flag, the existing element is converted to a stream object named CONTENTS and the new storage object is created containing the CONTENTS stream object. The destruction of the old element and the creation of the new storage object are both subject to the transaction mode on the parent storage object.

If a storage object with the same name already exists and grfMode is set to STGM_FAILIFTHERE, this method fails with the return value STG_E_FILEALREADYEXISTS.

See Also

IStorage - Compound File Implementation, IStorage::OpenStorage