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

Article View: borland.public.cppbuilder.multimedia

Article #3

Back to borland.public.cppbuilder.multimedia Previous Next

From: Maynard Philbrook
Date: Wed, 05 Mar 2003 07:14

41 lines
2708 bytes

pCanvas->Canvas->?????


Joseph wrote:

> 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

Technical Details

Message-ID: <3E65A3F3.A5886863@mindspring.com>

Path:

arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!sn-xit-02!sn-xit-03!sn-xit-06!sn-xit-08!supernews.com!207.217.77.43.MISMATCH!newsfeed1.earthlink.net!newsfeed.earthlink.net!stamper.news.pas.earthlink.net!stamper.news.atl.earthlink.net!harp.news.atl.earthlink.net!not-for-mail

References: <7b424d28.0303042203.21e36935@posting.google.com>

Show Full Headers

Complete Article Headers

X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 10e433,69eca6f308d0a81a
X-Google-Attributes: gid10e433,public
X-Google-Thread: 10cc67,69eca6f308d0a81a
X-Google-Attributes: gid10cc67,public
X-Google-Thread: 10d0fc,69eca6f308d0a81a
X-Google-Attributes: gid10d0fc,public
X-Google-Thread: 101d59,69eca6f308d0a81a
X-Google-Attributes: gid101d59,public
X-Google-Thread: f5ca7,69eca6f308d0a81a
X-Google-Attributes: gidf5ca7,public
X-Google-ArrivalTime: 2003-03-04 23:17:16 PST
Path: arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!sn-xit-02!sn-xit-03!sn-xit-06!sn-xit-08!supernews.com!207.217.77.43.MISMATCH!newsfeed1.earthlink.net!newsfeed.earthlink.net!stamper.news.pas.earthlink.net!stamper.news.atl.earthlink.net!harp.news.atl.earthlink.net!not-for-mail
From: Maynard Philbrook <UseThis.jamie12@mindspring.com>
Newsgroups: borland.public.cppbuilder.multimedia,borland.public.cppbuilder.nativeapi,borland.public.cppbuilder.graphics,borland.public.cppbuilder.winapi,borland.public.cppbuilder.vcl.components.writing
Subject: Re: How do I draw on TCanvas from inside a function call ?
Date: Wed, 05 Mar 2003 02:14:59 -0500
Organization: MindSpring Enterprises
Lines: 42
Message-ID: <3E65A3F3.A5886863@mindspring.com>
References: <7b424d28.0303042203.21e36935@posting.google.com>
Reply-To: UseThis.jamie12@mindspring.com
NNTP-Posting-Host: 44.76.b2.0c
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Server-Date: 5 Mar 2003 07:17:14 GMT
X-Mailer: Mozilla 4.5 [en]C-CCK-MCD {TLC;RETAIL}  (Win98; U)
X-Accept-Language: en

Reply to Parent Message