?
Solved

Pointers in Delphi 32

Posted on 1998-01-02
2
Medium Priority
?
943 Views
Last Modified: 2008-02-26
My problem is, I have to increment a pointer.
    In old 16 bit code, I does it by use
   p := ptr(seg(p^),ofs(p^) + n);
    but this is not longer possible in delphi 32. So how can I do the
same stuff in 32bit?
    Here is some dummy code to make my problem more understandable...
    Type
   Rec = record
      size: integer;
      data: array[0..0] of byte;
   end;
   prec = ^rec;
   procedure readmorerecs;
   var
  p : pointer;
  numberofrec: integer;
   begin
  filestream := tfilestream.create('somefile',fmopenread);
  getmem(p,filestream.size);
  filestream.read(numberofrec,sizeof(integer));
  filestream.read(p^,filestream.size);
  interpretrec(p,numberofrec);
  filestream.free;
   end;
   procedure interpretrecs(var p; numberofrec: integer);
   var
  myrec: prec;
   begin
  myrec := @p;
  while numberofrec > 0 do
  with myrec^ do
  begin
   dosomething with myrec
   // not possible in 32 bit
   myrec := Ptr(Seg(myrec^),Ofs(myrec^)+Size);
   dec(numberofrec);
  end;
   end; *)

--
info@cpfreiburg.de
0
Comment
Question by:karlhfreiburg
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 1

Accepted Solution

by:
hustch earned 200 total points
ID: 1355110
In Delphi 32, you don't use the segment any more, the 32-bit pointer is an offset.
You can add Size to your pointer directly. If the Compiler won't let you do it with a pointer of type prec, you can typecast it to type PChar (myrec := prec(PChar(myrec)+size);)
0
 
LVL 5

Expert Comment

by:julio011597
ID: 1355111
Maybe Size here is meant to be SizeOf(Rec)
0

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

A lot of questions regard threads in Delphi.   One of the more specific questions is how to show progress of the thread.   Updating a progressbar from inside a thread is a mistake. A solution to this would be to send a synchronized message to the…
Objective: - This article will help user in how to convert their numeric value become words. How to use 1. You can copy this code in your Unit as function 2. than you can perform your function by type this code The Code   (CODE) The Im…
Have you created a query with information for a calendar? ... and then, abra-cadabra, the calendar is done?! I am going to show you how to make that happen. Visualize your data!  ... really see it To use the code to create a calendar from a q…
How to fix incompatible JVM issue while installing Eclipse While installing Eclipse in windows, got one error like above and unable to proceed with the installation. This video describes how to successfully install Eclipse. How to solve incompa…
Suggested Courses

649 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question