Freeing components

Do I have to close free all objects created with Free
before terminating application, or all of them are
automatically free-ed?
bor061297Asked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
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.

mvz121697Commented:
As a general rule:
Free all components which you are creating yourself,
with the Create-method.
So if you are dropping components on your form, don't worry about freeing, Delphi does it for you.

But if you are creating components dynamicly, you have to free them, like this:

var fm:TForm;
begin
fm:=TForm.create(Self);
try
  // stuff...
   fm.ShowModal;
finally  
  fm.Free;
end;


BTW, if you don't follow this rule for VCL-components,
they will still automaticly be freed, when the parent is destroyed. (The parent is the object you supply as a parameter in the create-method).  
You can also let the Application be the parent, like this:

fm:=TForm.Create(Application)

If you don't free this yourself, it will be freed when the application ends.


Greetings,
MvZ




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
d003303Commented:
just a little cosmetics, the owner is passed in the Create method. Also, if the owner is freed, all owned components are freed, too. This does not depend on the parent property.
Generally, all components on a form are owned by the form. If e.g. a label resists on a panel wich resists on a form, the owner property of all two components is the form. The parent of the label though is the panel, the parent of the panel is the form. And normally all forms are owned by the application and have no parents (except MDIChild wich has the MDIForm as a parent).

Slash/d003303
0
bor061297Author Commented:
If I create a BitMap with:

Bitmap := TBitMap.Create;

is it automatically freed when application ends?
And, who owns Bitmap created in this way
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.