SetLength and pointers

I'll try and confuse everyone as little as possible here.

I have a record. It is called email_info. This record is basically an e-mail account.
I have email_accounts which is an array of email_info.

I add new accounts to a list (similar to a treeview i guess.) when the user mouses over, they see a tooltip (hint) containting data from that account. i.e. new messages, etc..

Problem. When I add a new record (account) I call SetLength(email_accounts, Length(email_accounts) +1)

this moves my array to a different location in memory. so when i add a new account, the accounts above it don't know where to grab their data. so i usually get some funky stuff in there.

what would solve this? a pointer to the pointer that's already in the tooltip?

this is probably VERY confusing, sorry :)
gwarguitarAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

j42Commented:
I can see two ways:

1. Don't store the address of your record but the index in the array instead
2. Don't use records at all. Define a class to store your email info and
   use a TObjectList as container.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
DeerBearCommented:
Hi,

I basically second j42 here, but I would add some insight on the matter.

First of all, we've no clue of the record structure( yes, it matters ) and I
think you're using LongStrings in it, right? <g>

If I was you, in order to have a safe move, I'd do this:

procedure ExpandEmailArray( SrcArr : array of TEmailInfo;Delta : Integer;var DstArr : array of TEmailInfo );

var SrcLen : Integer;
      Elem_Idx : Integer;
begin
   SrcLen := Length( SrcArr );
   SetLengthDstArr( DstArr,Delta );
   for Elem_Idx := 0 to Pred( SrcLen ) do
   begin
      DstArr[ Elem_Idx ] := SrcArr[ Elem_Idx ];
   end;
end;

Anyway, an OO approach would definitely better.

HTH,

Andrew
0
gwarguitarAuthor Commented:
1. Don't store the address of your record but the index in the array instead

that put me on the right track, thanks, guys.
0
j42Commented:
You're welcome.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Delphi

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.