Date: Sat, 23 Feb 2002 14:21:30 +0100
Newsgroups: borland.public.delphi.objectpascal
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Subject: Re: Creating a bitmap from form
From: "Peter Below (TeamB)" <100113.1101@compuXXserve.com>
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In article <3c77077d_2@dnews>, Rafael Cotta wrote:
> I have a program that draws on Form.Canvas and use some TStaticText, and,
> and a Memo that together form a picture.
> How can I define a rectangle and save this as a bitmap (if I can save as
> PNG, even better!). I mean, save what I can see as a bitmap, with memo,
> canvas and statictext.

You can create a canvas for the complete screen and copy a part of that to 
a bitmaps canvas. If you define the rectangle on the form (so in the forms 
client coordinates) you need to convert that to screen-relative 
coordinates. Example (untesed!):

Procedure CopyFormrectToBitmap( aForm: Tform; aRect: TRect; 
  aBitmap: TBitmap );
Var
  cv: TCanvas;
Begin
  Assert( Assigned( aform ));
  Assert( Assigned( aBitmap ));
  cv:= TCanvas.Create;
  try
    cv.Handle := CreateDC( 'DISPLAY', Nil, Nil, Nil );
    try
      MapWindowPoints( aForm.handle, HWND_DESKTOP, aRect, 2 );
      aBitmap.Width := arect.right - arect.left;
      aBitmap.Height := arect.bottom - arect.top;
      aBitmap.Canvas.Copymode := cmSrcCopy;
      aBitmap.Canvas.CopyRect( aBitmap.Canvas.Cliprect, cv, aRect );
    finally
      DeleteDC( cv.Handle );
      cv.Handle := 0;
    End; { Try finally }
  Finally
    cv.free;
  End;{ Try finally }
End;      

You need to pass an existing bitmap instance to the procedure, which you 
can then save to file. For PNG you need to find some conversion routine or 
component on the web. Search one of the sites below.

   http://www.borland.com/delphi/resources/deltools.html
Delphi Super Page       http://sunsite.icm.edu.pl/delphi/ 
  US mirror site:       http://www.cdrom.com/pub/delphi_www/ 
  German mirror :        
http://ftp.uni-erlangen.de/pub/source/MIRRORS/sunsite.icm.edu.pl/pub/delphi
  Other mirrors :       http://ftp.sunet.se/delphi/ 
Torry's Delphi Pages    http://www.torry.net/  
                        http://homepages.borland.com/torry/
the Delphi Box          http://Inner-Smile.com .
                        http://www.delphisource.com/ 
The DELPHI Deli         http://www.delphix.com/
The Delphi EXchange     http://www.delphiexchange.com/
The Delphi Pool         http://www.lmc-mediaagentur.de/dpool.htm



--
Peter Below (TeamB)  100113.1101@compuserve.com)
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