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Matt

Delphi Developer
Mon, 23 Feb 2004 02:34:27 GMT

Problem drawing to main form canvas

I must be missing something simple, but I just can't get this to work.
I have a bitmap (in "pic"), and I want to draw it to the canvas of the
program's main form (called "form_main"). The line:
form_main.Canvas.Draw(0,0,pic);
Compiles, but does nothing at runtime.

I know my bitmap is okay, because when I draw to an image control on the
form:
form_main.Image1.Canvas.Draw(0,0,pic);
it works just fine.

Is there some secret "AllowDrawing" setting I'm missing somewhere?

Any help appreciated,
Thanks,
-Matt

 
Mauro Patin

Delphi Developer
Mon, 23 Feb 2004 03:33:52 GMT

Re:Problem drawing to main form canvas


Quote
Matt wrote:
> I must be missing something simple, but I just can't get this to work.
> I have a bitmap (in "pic"), and I want to draw it to the canvas of the
> program's main form (called "form_main"). The line:
> form_main.Canvas.Draw(0,0,pic);
> Compiles, but does nothing at runtime.

> I know my bitmap is okay, because when I draw to an image control on the
> form:
> form_main.Image1.Canvas.Draw(0,0,pic);
> it works just fine.

> Is there some secret "AllowDrawing" setting I'm missing somewhere?

Where are you placing your drawing code?

Any code that draws on the form's canvas should be in the OnPaint event.

Matt

Delphi Developer
Mon, 23 Feb 2004 04:35:08 GMT

Re:Problem drawing to main form canvas


That did it; thanks.

Quote
"Mauro Patino" <M-Pat...@govst.edu> wrote in message

news:3B967E1F.6C01D34D@govst.edu...
Quote
> Matt wrote:

> > I must be missing something simple, but I just can't get this to work.
> > I have a bitmap (in "pic"), and I want to draw it to the canvas of the
> > program's main form (called "form_main"). The line:
> > form_main.Canvas.Draw(0,0,pic);
> > Compiles, but does nothing at runtime.

> > I know my bitmap is okay, because when I draw to an image control on the
> > form:
> > form_main.Image1.Canvas.Draw(0,0,pic);
> > it works just fine.

> > Is there some secret "AllowDrawing" setting I'm missing somewhere?

> Where are you placing your drawing code?

> Any code that draws on the form's canvas should be in the OnPaint event.

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