I often use the Object property of listbox and TStringList items to store pointers, or just numbers for array subscripts. I don't see any problem doing that as it can save a lot of time. It is just an integer variable internally. I seem to remember coming across the same problem once (D7) and had to use -2 instead of -1 to indicate no value or something of that nature. I'm not sure why. The integer always exists and defaults to a value of 0.
Ross. -----Original Message----- From: delphi-boun...@delphi.org.nz [mailto:delphi-boun...@delphi.org.nz] On Behalf Of Alister Christie Sent: Tuesday, 16 February 2010 10:20 a.m. To: NZ Borland Developers Group - Delphi List Subject: Re: [DUG] Is it a bug in latest version of Delphi? I can confirm that ListBox1.Items.AddObject('foo', TObject(-1)); ShowMessage(IntToStr(Integer(ListBox1.Items.Objects[0]))); gives an error but ListBox1.Items.AddObject('foo', TObject(0)); ShowMessage(IntToStr(Integer(ListBox1.Items.Objects[0]))); does not I think casting -1 to an object is probably not the best idea - what memory location does this point to anyway? 0xFFFFFFFF? Alister Christie Computers for People Ph: 04 471 1849 Fax: 04 471 1266 http://www.salespartner.co.nz PO Box 13085 Johnsonville Wellington sinu sudhakaran wrote: > Hi all, > > I came across a strange bug(???) in latest versions of Delphi. > > Have a look at the following code. > > procedure TForm1.Button1Click(Sender: TObject); > var > i : integer; > begin > ComboBox1.Clear; > ComboBox1.Items.AddObject('All Locations', TObject(-1)); > ComboBox1.Items.AddObject('Only this Location', TObject(0)); > ComboBox1.Items.AddObject(Test Location', TObject(1)); > > i := Integer(ComboBox1.Items.Objects[0]); > showmessage(inttostr(i)); > end; > > When I tried to run this code in Delphi 6 and Delphi 2007 , I am > getting List Index out of bounds[0] error in Showmessage. When I tried > -2, -3, -4… instead of -1 object , I got the proper output without any > List index out of bounds error. Also I am getting -1 without any error > when I tried this code in Delphi 3. > > Is it a bug in latest version of Delphi ? Any help is appreciated. > > Thank you > > Regards, > Sinu > > <http://sigads.rediff.com/RealMedia/ads/click_nx.ads/www.rediffmail.com/signatureline....@middle?> > > > > ------------------------------------------------------------------------ > > _______________________________________________ > NZ Borland Developers Group - Delphi mailing list > Post: delphi@delphi.org.nz > Admin: http://delphi.org.nz/mailman/listinfo/delphi > Unsubscribe: send an email to delphi-requ...@delphi.org.nz with Subject: > unsubscribe _______________________________________________ NZ Borland Developers Group - Delphi mailing list Post: delphi@delphi.org.nz Admin: http://delphi.org.nz/mailman/listinfo/delphi Unsubscribe: send an email to delphi-requ...@delphi.org.nz with Subject: unsubscribe _______________________________________________ NZ Borland Developers Group - Delphi mailing list Post: delphi@delphi.org.nz Admin: http://delphi.org.nz/mailman/listinfo/delphi Unsubscribe: send an email to delphi-requ...@delphi.org.nz with Subject: unsubscribe
