Solved

StringList Objects

Posted on 1998-10-16
4
700 Views
Last Modified: 2013-11-23
I am interested in using the Objects property of a StringList to associate objects with certain Lines of a RichEdit. However, Delphi's help says that certain StringList objects ignore the Object property because "they don't make sense, like Lines in a Memo". I'm not sure exactly what that means but is there a way to associate Objects with Lines in a memo (or richedit) object?
0
Comment
Question by:jcglen
  • 2
4 Comments
 

Author Comment

by:jcglen
ID: 1343156
Edited text of question
0
 
LVL 12

Accepted Solution

by:
rwilson032697 earned 50 total points
ID: 1343157
What the help is saying is that the designers of the TMemo (and probably TRichEdit) objects couldn't think of a reason to do it and so didn't.

The easiest way is to have a TList that stores the objects. You could match the index of a line of text in the lines property to the index of an object in the TList object.

You will need to manage what happens when the user deletes/adds lines etc whch may be a little awkward, but if it is to be read-only this should be fine...

Cheers,

Raymond.
 
0
 
LVL 1

Expert Comment

by:Edo082297
ID: 1343158
Hello jcglen
   Associating line indexes with TList pointers is not a good idea in my opinion. I use the Objects member (or related Data member in TListItems) a lot because they are very useful. There are two ways to do what you are trying to do. First of all, since the Lines property of a TRichEdit is itself of type TStrings, you could associate your object with Lines.Objects. The second more complicated thing keeps your objects associated with your string list (which is what you want to do, right?).

First, declare a small class, called TLine:

  TLine = class
  private
    FLine : String;
  end;

Now, to associate a given line with your object, create an object of type TLine and associate it with your string list member.

  MyLine := TLine.Create;
  MyLine.FLine := RichEdit1.Lines[y];
  MyStringList.Objects[x] := MyLine;

Now you have kept the text in your string list and have an associated object. You can dereference the string like this:
 
  TLine(MyStringList.Objects[AnIndex]).FLine;

You can also search your stringlist using IndexOf, IndexOfObject, and so on (just like you can with Lines). The Objects and Data members of various classes in Delphi are very powerful in this regard.

Finally, in your destructor, you have to free the memory you have allocated for each of these objects. Do the following:

  for i := 0 to Pred(MyStringList.Count) do
    TLine(MyStringList.Objects[x]).Free;

Regards,
Edo

0
 
LVL 1

Expert Comment

by:Edo082297
ID: 1343159
I am tired, there is a mistake in the destructor, [x] should read [i].

0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

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

The uses clause is one of those things that just tends to grow and grow. Most of the time this is in the main form, as it's from this form that all others are called. If you have a big application (including many forms), the uses clause in the in…
Introduction I have seen many questions in this Delphi topic area where queries in threads are needed or suggested. I know bumped into a similar need. This article will address some of the concepts when dealing with a multithreaded delphi database…
With Secure Portal Encryption, the recipient is sent a link to their email address directing them to the email laundry delivery page. From there, the recipient will be required to enter a user name and password to enter the page. Once the recipient …
With Secure Portal Encryption, the recipient is sent a link to their email address directing them to the email laundry delivery page. From there, the recipient will be required to enter a user name and password to enter the page. Once the recipient …

943 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

Need Help in Real-Time?

Connect with top rated Experts

19 Experts available now in Live!

Get 1:1 Help Now