UCOMIStream Interface



This API is now obsolete.

Use IStream instead.

public interface class UCOMIStream
[System.Obsolete("Use System.Runtime.InteropServices.ComTypes.IStream instead. https://go.microsoft.com/fwlink/?linkid=14202", false)]
public interface UCOMIStream
type UCOMIStream = interface
Public Interface UCOMIStream


For more information, please see the existing documentation for IStream and ISequentialStream in the com subfolder of the MSDN library.



Creates a new stream object with its own seek pointer that references the same bytes as the original stream.


Ensures that any changes made to a stream object open in transacted mode are reflected in the parent storage.

CopyTo(UCOMIStream, Int64, IntPtr, IntPtr)

Copies a specified number of bytes from the current seek pointer in the stream to the current seek pointer in another stream.

LockRegion(Int64, Int64, Int32)

Restricts access to a specified range of bytes in the stream.

Read(Byte[], Int32, IntPtr)

Reads a specified number of bytes from the stream object into memory starting at the current seek pointer.


Discards all changes that have been made to a transacted stream since the last Commit(Int32) call.

Seek(Int64, Int32, IntPtr)

Changes the seek pointer to a new location relative to the beginning of the stream, to the end of the stream, or to the current seek pointer.


Changes the size of the stream object.

Stat(STATSTG, Int32)

Retrieves the STATSTG structure for this stream.

UnlockRegion(Int64, Int64, Int32)

Removes the access restriction on a range of bytes previously restricted with LockRegion(Int64, Int64, Int32).

Write(Byte[], Int32, IntPtr)

Writes a specified number of bytes into the stream object starting at the current seek pointer.

Applies to