what's the differences between AParam: P[Type] and var AParam: [Type] in dll import.

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2 total messages Started by nhsoft.xy Thu, 08 Dec 2005 14:45

#55

Author: nhsoft.xy
Date: Thu, 08 Dec 2005 14:45

29 lines
1996 bytes

what's the differences between AParam: P[Type] and var AParam: [Type]
in dll import.
eg.
//C declaration:
//WORD DC_Mif_AntiCollision (DWORD *_dwSnr, BYTE _bMode = 1);
function DC_Mif_AntiCollision(var _dwSnr: Dword):WORD;Stdcall;external
'FOX_DC.dll';
function DC_Mif_AntiCollision(_dwSnr:PDword):WORD;Stdcall;external
'FOX_DC.dll';


And which is better. (It's a mifare1 api to operate IC Card Reader)
eg.
var
  dword_1: PDWORD;
  dword_2: DWORD;
begin
  //function DC_Mif_AntiCollision(var _dwSnr:
Dword):WORD;Stdcall;external 'FOX_DC.dll';
  GetMem(dword_1, SizeOf(DWORD));
  DC_Mif_AntiCollision(dword_1);
  DC_Mif_AntiCollision(dword_2);

  //function DC_Mif_AntiCollision(_dwSnr:PDword):WORD;Stdcall;external
'FOX_DC.dll';
  DC_Mif_AntiCollision(@dword_2);
  //TODO: which one is better???
end;
which one is better, and why?

Re: what's the differences between AParam: P[Type] and var AParam: [Type] in dll import.

#56

Author: Riki Wiki
Date: Sun, 11 Dec 2005 19:16

10 lines
1277 bytes

Hoi

You need to repost your question on the Borland news server to make
everybody see it and possibly answer your question. Further, this newsgroup
do not officially exist, use newsgroup b.p.d.language.delphi.general.

Take a look here:
<http://tinyurl.com/8m5nw>
which links to
<http://delphi.wikicities.com/wiki/Delphi_Newsgroups>

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