Hi

I've trolled around looking for an answer to this one and concluded
that I must be missing something basic.

I'm trying to load a JPEG into a field, plus a thumbnail in another
field.

It is failing on the marked statement with the message "Bitmap image is
not valid." regardless of which JPEG file I select - and why is the
thing worried about bitmap when I'm working with JPEG?

The code is below:-

procedure TfrmMain.btnLoadPhotoClick(Sender: TObject);
const
 MaxHeight: integer = 50;
var
 oJPG: TJPEGImage;
 oBmp: TBitmap;
 iHeight, iWidth: integer;
 Stream: TMemoryStream;
 iniFile: TInifile;
begin
 oJPG := TJPEGImage.Create;
 oBmp := TBitmap.Create;
 Stream := TMemoryStream.Create;
 iniFile := TInifile.Create('JvDBUltimGrid.ini');
 try
   OpenPictureDlg.InitialDir := iniFile.ReadString('Images', 'Folder',
'');
   if (OpenPictureDlg.Execute) then
   begin
     try
       begin
         iniFile.WriteString('Images', 'Folder',
           ExtractFilePath(OpenPictureDlg.FileName));
         oJPG.LoadFromFile(OpenPictureDlg.FileName);
         tblPhotosOriginalFileLocation.AsString :=
OpenPictureDlg.FileName;
       end
     except
       MessageDlg('Error while trying to open ' +
         OpenPictureDlg.FileName + '.', mtError, [mbOK], 0);
       exit;
     end;
     Stream.Position := 0;
     oJPG.SaveToStream(Stream);
     tblPhotosImage.LoadFromStream(Stream); <<< ERROR HERE!!!!<<<<<<<<<
     oBmp.Width := (oJPG.Width * MaxHeight) div oJPG.Height;
     oBmp.Height := MaxHeight;
     oBmp.Canvas.StretchDraw(Rect(0, 0, oBmp.Width - 1, oBmp.Height -
1), oJPG);
     oJPG.Assign(oBmp);
     oJPG.Compress;
     Stream.Clear;
     Stream.Position := 0;
     oJPG.SaveToStream(Stream);
     tblPhotosThumbNail.LoadFromStream(Stream);
   end;
 finally
   oBmp.Free;
   oJPG.Free;
   Stream.Free;
   iniFile.Free;
 end;
end;
===============================
Cheers

Jeff
--
Jeff Cook
Aspect Systems Ltd
www.aspect.co.nz
+
Joan and Jeff Cook
The Cooks Oasis
www.cookislandsoasis.com

Oops, forgot ...

DBISAM v3.30, Delphi 6

--
Jeff Cook
Aspect Systems Ltd
www.aspect.co.nz
+
Joan and Jeff Cook
The Cooks Oasis
www.cookislandsoasis.com

Further info.  

If I comment out the offending line, it goes ahead and succesfully
loads the other blob field with the resized image.  I can export the
resulting field with DBSYS and the exported file opens successfully as
a smaller .jpg.

Very weird!


--
Jeff Cook
Aspect Systems Ltd
www.aspect.co.nz
+
Joan and Jeff Cook
The Cooks Oasis
www.cookislandsoasis.com

Jeff Cook wrote:

>
> Further info.  
>
> If I comment out the offending line, it goes ahead and succesfully
> loads the other blob field with the resized image.  I can export the
> resulting field with DBSYS and the exported file opens successfully as
> a smaller .jpg.
>
> Very weird!

Yet more info ... I have workaround the problem by simply using a
LoadFromFile for blob field.  It means I load it twice, once for the
field and once for resizing but ...

--
Jeff Cook
Aspect Systems Ltd
www.aspect.co.nz
+
Joan and Jeff Cook
The Cooks Oasis
www.cookislandsoasis.com

"Jeff Cook" <jeffc@aspect.co.nz> wrote in message
news:3834E25C-C1A2-43B8-9E65-539F1F1DF8C3@news.elevatesoft.com...
> Jeff Cook wrote:
>
>>
>> Further info.
>>
>> If I comment out the offending line, it goes ahead and succesfully
>> loads the other blob field with the resized image.  I can export the
>> resulting field with DBSYS and the exported file opens successfully as
>> a smaller .jpg.
>>
>> Very weird!
>
> Yet more info ... I have workaround the problem by simply using a
> LoadFromFile for blob field.  It means I load it twice, once for the
> field and once for resizing but ...
>
> --

what happens if you reset the stream position just before the

"tblPhotosImage.LoadFromStream(Stream); <<< ERROR HERE!!!!<<<<<<<<<"

Jeff,

<< It is failing on the marked statement with the message "Bitmap image is
not valid." regardless of which JPEG file I select - and why is the thing
worried about bitmap when I'm working with JPEG? >>

Is there a TDBImage control attached to the tblPhotosImage TField ?  What
data type is that TField defined as ?

--
Tim Young
Elevate Software
www.elevatesoft.com

Frans,

<< what happens if you reset the stream position just before the >>

The stream position should be set to 0 automatically by the LoadFromStream
method - it calls the TStream.CopyFrom method with a 0 parameter.

--
Tim Young
Elevate Software
www.elevatesoft.com

Frans van Daalen wrote:

>
>
> what happens if you reset the stream position just before the
>
> "tblPhotosImage.LoadFromStream(Stream); <<< ERROR HERE!!!!<<<<<<<<<"

That's it.  Perfect!

Meitaki maata

Jeff

--
Jeff Cook
Aspect Systems Ltd
www.aspect.co.nz
+
Joan and Jeff Cook
The Cooks Oasis
www.cookislandsoasis.com

Tim Young [Elevate Software] wrote:

> Jeff,
>
> << It is failing on the marked statement with the message "Bitmap
> image is not valid." regardless of which JPEG file I select - and why
> is the thing worried about bitmap when I'm working with JPEG? >>
>
> Is there a TDBImage control attached to the tblPhotosImage TField ?
> What data type is that TField defined as ?

There is a TJvDBImage connected to the field and it is defined as a
blob.  As per my reply to Frans - setting the stream position to zero
seems to have so solved the problem.

Code now looks like:-

   if (OpenPictureDlg.Execute) then
   begin
     try
       begin
         iniFile.WriteString('Images', 'Folder',
           ExtractFilePath(OpenPictureDlg.FileName));
         oJPG.LoadFromFile(OpenPictureDlg.FileName);
         tblPhotosOriginalFileLocation.AsString :=
OpenPictureDlg.FileName;
       end
     except
       MessageDlg('Error while trying to open ' +
         OpenPictureDlg.FileName + '.', mtError, [mbOK], 0);
       exit;
     end;
     oJPG.SaveToStream(Stream);
     Stream.Position := 0;
     tblPhotosImage.LoadFromStream(Stream);
..
..
..

Cheers

Jeff

--
Jeff Cook
Aspect Systems Ltd
www.aspect.co.nz
+
Joan and Jeff Cook
The Cooks Oasis
www.cookislandsoasis.com

Jeff,

<< There is a TJvDBImage connected to the field and it is defined as a blob.
As per my reply to Frans - setting the stream position to zero seems to have
so solved the problem. >>

That's really weird - the LoadFromStream method should set the position to 0
before loading.

--
Tim Young
Elevate Software
www.elevatesoft.com