How to copy from canvas to tbitmap.canvas

Christian Schneider

Delphi Developer

Sat, 17 Jul 2004 04:00:18 GMT

How to copy from canvas to tbitmap.canvas

"leapin" <wa...@resa.net> schrieb im Newsbeitrag news:3c55ac9a$1_1@dnews...

Quote

> var map : TBitMap;
> Form1.OnDeactivate;
> Begin
> Form1.Canvas := map.canvas;
> {I've tried several methos with no success}
> End;

> This gives me that form1.Canvas is read only;

> I want to save my picture on the forms Deactivate. (fastest file, stream?)
> I want to load my picture on the forms Activate.
> Any sample code would be awsome.
> Thanks

Take a look at the following code

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
var bmp : TBitmap;
begin
bmp := TBitmap.Create;
bmp.Width := Width;
bmp.Height := Height;

//Copys the Forms Canvas into the Bitmaps Canvas
BitBlt( bmp.Canvas.Handle,
0, 0, Width, Height,
Canvas.Handle,
0, 0, SRCCOPY );

bmp.SaveToFile( 'C:\FormClose.bmp');
bmp.Free;
end;

Christian

leapi

Delphi Developer

Sat, 17 Jul 2004 03:54:37 GMT

Re:How to copy from canvas to tbitmap.canvas

var map : TBitMap;
Form1.OnDeactivate;
Begin
Form1.Canvas := map.canvas;
{I've tried several methos with no success}
End;

This gives me that form1.Canvas is read only;

I want to save my picture on the forms Deactivate. (fastest file, stream?)
I want to load my picture on the forms Activate.
Any sample code would be awsome.
Thanks

Seth Kinti

Delphi Developer

Sun, 18 Jul 2004 07:49:34 GMT

Re:How to copy from canvas to tbitmap.canvas

Quote

"Christian Schneider" <cw...@pgcenter.de> wrote in message <news:3c55ae80_2@dnews>...
> "leapin" <wa...@resa.net> schrieb im Newsbeitrag news:3c55ac9a$1_1@dnews...
> > var map : TBitMap;
> > Form1.OnDeactivate;
> > Begin
> > Form1.Canvas := map.canvas;
> > {I've tried several methos with no success}
> > End;

> > This gives me that form1.Canvas is read only;

> > I want to save my picture on the forms Deactivate. (fastest file, stream?)
> > I want to load my picture on the forms Activate.
> > Any sample code would be awsome.
> > Thanks

> Take a look at the following code

> procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
> var bmp : TBitmap;
> begin
> bmp := TBitmap.Create;
> bmp.Width := Width;
> bmp.Height := Height;

> //Copys the Forms Canvas into the Bitmaps Canvas
> BitBlt( bmp.Canvas.Handle,
> 0, 0, Width, Height,
> Canvas.Handle,
> 0, 0, SRCCOPY );

> bmp.SaveToFile( 'C:\FormClose.bmp');
> bmp.Free;
> end;

> Christian

Form canvases loose their info if you drag them off the screen or
cover them up.

Timage.canvases don't, and they have a method to save as a bitmap. I
don't know if that's a better way or not, just fyi.

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