I stepped through your code in D6 (don't have D5 installed on this machine) - but perhaps there is something wrong in D5? I am wondering in D5 whether TGraphic's constructor is protected?
Dennis. ----- Original Message ----- From: "Jianming Lin (ASL)" <[EMAIL PROTECTED]> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]> Sent: Friday, October 18, 2002 9:10 AM Subject: RE: [DUG]: polymorphism problem > > > -----Original Message----- > From: Dennis Chuah [mailto:dennis_cs_chuah@;hotmail.com] > Sent: Friday, 18 October 2002 7:14 a.m. > To: Multiple recipients of list delphi > Subject: Re: [DUG]: polymorphism problem > > > > I stepped through your code and it *DEFINITELY* calls TMetadata.Create. > What you have done looks correct and this is certainly not a polymorphism > pproblem. Few suggestions: > > 1. Check that you do not have $(DELPHI)\Lib in your project path - it > should only be in the global library path. > > Checked > > 2. What if you replaced your code with: > NGraphic := TMetadata.Create; > > Step through the code - does it call TMetadata.Create? > > Yes it does > > 3. Check the class type of NGraphic and compare Pointer(NGraphic.ClassType) > against Pointer(TMetadata). Are they the same pointer values? > > Checked. still not get called. > > What version of Delphi are you using? > > D5 Ent > > > Dennis. > > ----- Original Message ----- > From: Jianming Lin (ASL) > To: Multiple recipients of list delphi > Sent: Thursday, October 17, 2002 4:35 PM > Subject: [DUG]: polymorphism problem > > > > > G'Day, guys, > > procedure TryMetadata(ImgType : Integer); > var NGraphic: TGraphic; > GraphicClass: TGraphicClass; > begin > ImgType := 1; > case ImgType of > 1 : GraphicClass := TMetaFile; > 2 : GraphicClass := TBitmap; > end; > NGraphic := GraphicClass.Create; > end; > > > Why constructor of TMetafile.Create is not called instead only > TObject.Create is called? > > > > > > [Jianming Lin (ASL)] > > > > > > This e-mail message has been scanned for Viruses and Content and cleared by > MailMarshal - For more information please visit www.marshalsoftware.com > -------------------------------------------------------------------------- - > New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED] > Website: http://www.delphi.org.nz > To UnSub, send email to: [EMAIL PROTECTED] > with body of "unsubscribe delphi" > Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/ > > ############################################################################ ######### > This e-mail message has been scanned for Viruses and Content and cleared > by MailMarshal > For more information please visit www.marshalsoftware.com > ############################################################################ ######### > -------------------------------------------------------------------------- - > New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED] > Website: http://www.delphi.org.nz > To UnSub, send email to: [EMAIL PROTECTED] > with body of "unsubscribe delphi" > Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/ > --------------------------------------------------------------------------- New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED] Website: http://www.delphi.org.nz To UnSub, send email to: [EMAIL PROTECTED] with body of "unsubscribe delphi" Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/
