Firstly, you should not use pointers when using classes unless it is
absolutely necessary. This is because an object reference is implicitly a
pointer. Let Delphi handle the pointer math for you.
Secondly, do not use GetMem to instantiate a class. GetMem only reserves
memory. It does not initialise the object, eg. it does not set the VMT
pointer.
So to summarise, what you should have done is:
type
TMain = class
private
connect: array[1..maxNum] of TMain;
...
end;
procedure Button1Click
var
M: TMain;
begin
M := TMain.Create;
M.Init;
end;
Hope this helps.
----- Original Message -----
From: "Gajo Istvan" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, December 22, 2003 1:48 AM
Subject: [DUG] Error with pointers
> Hello, I'm new to pointers, and I have a problem that I think is easy to
> solve. I get an EAccessViolation when trying to initialize my object with
> the Init procedure. The carret points at "elem", or in other words, I
think
> I'm trying to access M.elem without M being initialized. But M IS
> initialized, at least I think so!
> So what's wrong?
>
> type
> Main = ^MainType;
> MainType = class
> private
> connect: array[1..maxNum] of Main;
> elem: integer;
> public
> procedure Init;
> procedure KillObj;
> end;
>
> ...
>
> procedure MainType.Init;
> var
> i: integer;
> begin
> elem := 0;
> for i := 1 to maxNum do
> connect[i] := nil
> end;
>
> ...
>
> procedure Button1Click
> var
> M: Main;
> begin
> GetMem(M, SizeOf(M));
> G.Init;
> G.KillObj
> end;
>
>
> _______________________________________________
> Delphi mailing list
> [EMAIL PROTECTED]
> http://ns3.123.co.nz/mailman/listinfo/delphi
>
_______________________________________________
Delphi mailing list
[EMAIL PROTECTED]
http://ns3.123.co.nz/mailman/listinfo/delphi
