How do I draw on TCanvas from inside a function call ?

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From: Joseph
Date: Wed, 05 Mar 2003 06:03

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Hello All,

Is it possible to draw on TControlCanvas from inside a function call ?

I mean ...

   void __fastcall TForm1::ShowTabSheet (Object *Sender) {
   
        TControlCanvas *pCanvas = new TControlCanvas ;
        
        pCanvas->Control = Tabsheet ;  // ie., TForm1::Tabsheet. Need to draw
                                       // on TabSheet, not on the main Form.

        DrawOnCanvas ( pCanvas ) ;  //** I need to draw on pCanvas from here 

        delete pCanvas ; 
   };



   void TForm1::DrawOnCanvas ( TControlCanvas *CANVAS ) {

       CANVAS->Pen->Color = clBlue ;
       CANVAS->MoveTo(0,0);
       CANVAS->LineTo(100,200);

   };


 ... This compiles and Links OK, but when I run it I get an error
message saying that "Canvas does not allow drawing". If I do the
drawing from inside the calling function, it's ok. But if done via a
function call, it won't draw.

Is the above the appropriate way of drawing on TControlCanvas from
inside a function ?



Regards,
Joseph 76

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From: joseph.redimerio@baesystems.com (Joseph)
Newsgroups: borland.public.cppbuilder.multimedia,borland.public.cppbuilder.nativeapi,borland.public.cppbuilder.graphics,borland.public.cppbuilder.winapi,borland.public.cppbuilder.vcl.components.writing
Subject: How do I draw on TCanvas from inside a function call ?
Date: 4 Mar 2003 22:03:19 -0800
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