IStream::Seek

A version of this page is also available for

Windows Embedded CE 6.0 R3

4/8/2010

This method changes the seek pointer to a new location relative to the current seek pointer or the beginning or end of the stream.

Syntax

HRESULT Seek( 
  ULARGE_INTEGER dlibMove, 
  DWORD dwOrigin, 
  ULARGE_INTEGER plibNewPosition 
);

Parameters

• dlibMove
  [in] Displacement to be added to the location indicated by the dwOrigin parameter. If dwOrigin is STREAM_SEEK_SET, this is interpreted as an unsigned value rather than signed.

• dwOrigin
  [in] Origin for the displacement specified in dlibMove. The origin can be the beginning of the file, the current seek pointer, or the end of the file.

• plibNewPosition
  [out] Pointer to the location where this method writes the value of the new seek pointer from the beginning of the stream.

  You can set this pointer to NULL to indicate that you are not interested in this value. In this case, this method does not provide the new seek pointer.

Return Value

The following table shows the return values for this method.

Remarks

IStream::Seek changes the seek pointer so that subsequent reads and writes can take place at a different location in the stream object.

It is an error to seek before the beginning of the stream.

It is not, however, an error to seek past the end of the stream. Seeking past the end of the stream is useful for subsequent writes, as the stream will at that time be extended to the seek position immediately before the write is done.

You can also use this method to obtain the current value of the seek pointer by calling this method with the dwOrigin parameter set to STREAM_SEEK_CUR and the dlibMove parameter set to zero so the seek pointer is not changed.

The current seek pointer is returned in the plibNewPosition parameter.

To determine whether the platform supports this interface, see Determining Supported COM APIs.

Requirements