[DUG] Jpg Image List

[Alister Christie]

I think I've got things sorted here is some example code (it still needs 
a lot of work for it to be useful).

I think my strategy will be to stream out a number of JpegImages and 
then stream them back - which effectly get me a list of images.

procedure TForm1.BitBtn1Click(Sender: TObject);
begin
   WriteMultipleGraphics([Image2.Picture.Graphic, Image1.Picture.Graphic]);
end;

procedure TForm1.BitBtn2Click(Sender: TObject);

begin
   ReadMultipleGraphics([Image1.Picture.Graphic, Image2.Picture.Graphic]);
end;

procedure TForm1.ReadMultipleGraphics(g: array of TGraphic);
var
   ms : TMemoryStream;
   fs : TFileStream;
   i : integer;
   size : integer;
begin
   ms := TMemoryStream.Create;
   fs := TFileStream.Create(MyFileName, fmOpenRead);
   for i := low(g) to high(g) do
   begin
     ms.Clear;
     fs.Read(Size, Sizeof(Size));
     ms.CopyFrom(fs, Size);
     ms.Position := 0;
     g[i].LoadFromStream(ms);
   end;
   FreeAndNil(ms);
   FreeAndNil(fs);
end;

procedure TForm1.WriteMultipleGraphics(g: array of TGraphic);
var
   ms : TMemoryStream;
   fs : TFileStream;
   i : integer;
   size : integer;
begin
   ms := TMemoryStream.Create;
   fs := TFileStream.Create(MyFileName, fmCreate);
   for i := low(g) to high(g) do
   begin
     ms.Clear;
     g[i].SaveToStream(ms);
     size := ms.Size;
     ms.Position := 0;
     fs.Write(Size, Sizeof(Size));
     ms.SaveToStream(fs);
   end;
   FreeAndNil(ms);
   FreeAndNil(fs);
end;

Alister Christie
Computers for People
Ph: 04 471 1849 Fax: 04 471 1266
http://www.salespartner.co.nz
PO Box 13085
Johnsonville
Wellington


Jeremy North wrote:
> You could stream many instances of TJpegImage to a file though and
> read them back in. The ImageList is a windows control and it only
> supports bitmaps, regardless of what is in your uses clause.
> 
> 
>>Yes but a TList is not streamable.  What I want to be able to achieve is
>>store a large number of JPEGImages efficiently in a single file.
> 
> 
> _______________________________________________
> Delphi mailing list
> Delphi at ns3.123.co.nz
> http://ns3.123.co.nz/mailman/listinfo/delphi
> 
>