IStream::SetSize  1P_LY.1

Changes the size of the stream object.

HRESULT SetSize(

Parameter

libNewSize

[in] Specifies the new size of the stream as a number of bytes.

Return Values

S_OK

The size of the stream object was successfully changed.

E_PENDING

Asynchronous Storage only: Part or all of the stream s data is currently unavailable. For more information see IFillLockBytes194LHM2 and Asynchronous Storage27PL.UQ.

STG_E_MEDIUMFULL

The stream size is not changed because there is no space left on the storage device.

STG_E_INVALIDFUNCTION

The value of the libNewSize parameter is not valid. Since streams cannot be greater than 232 bytes in the OLE-provided implementation, the high DWORD of libNewSize must be 0. If it is nonzero, this parameter is not valid.

STG_E_REVERTED

The object has been invalidated by a revert operation above it in the transaction tree.

Remarks

IStream::SetSize changes the size of the stream object. Call this method to preallocate space for the stream. If the libNewSize parameters larger than the current stream size, the stream is extended to the indicated size by filling the intervening space with bytes of undefined value. This operation is similar to the IStream::Write14LYPV method if the seek pointer is past the current end-of-stream.

If the libNewSize parameter is smaller than the current stream, then the stream is truncated to the indicated size.

The seek pointer is not affected by the change in stream size.

Calling IStream::SetSize can be  an effective way of trying to obtain a large chunk of contiguous space.

See Also

IStream - Compound File ImplementationAQSJQX, IStream::Write14LYPV