Jason,

It appears that whenever the CreateBlobStream method is passed a
bsmReadWrite mode-parameter, it's unable to read from the stream,
regardless of how the stream is created (from either a TIB_Query or
e.g. using TIB_BlobStream.CreateForColumn).

Using bsmRead when reading from the stream does work correctly, as
does bsmWrite when writing to the stream. But if it's not a bug,
what's the bsmReadWrite parameter for (implying you cannot read from
or write to the same stream) ?

Best regards,

Michael

--- In IBObjects@yahoogroups.com, jwharton@i... wrote:
> Use the TIB_Dataset.CreateBlobStream() method instead of directly
instantiating your own instance.
>
> Jason Wharton
> www.ibobjects.com
>
> -------------------------------------------------------------------
-------------
> -------------------------------------------------------------------
-------------
> Hi,
>
> I'm having trouble reading/writing from a blobstream. After
opening a
> TIB_Query with a blob field, I create the blobstream field:
>
> FStream := TIB_BlobStream (FDS.CreateBlobStream(FDS.FieldByName
> (FBlobFieldName), bsmReadWrite));
>
> If the mode is set to bsmReadWrite, the internal blobstream size
is
> set to 0, and all subsequent reads from the stream will fail. When
> using bsmRead, however, the size is assigned correctly, but
writing
> is not possible. The query is in edit mode and the blobfield is
not
> ReadOnly. In addition, when opening the field in bsmReadWrite
mode,
> I can write to the stream without any problems.
>
> Any suggestions will be highly appreciated.
>
> Best regards and thanks,
>
> Michael