MDI Child Close Event

I have an MDI application. I want to know if there is an event for child close.
i've tried :

  if Message.Msg=WM_MDIDESTROY then begin
     ShowMessage('Child closed');
  end else inherited WndProc(Message);

but it does not work. Can anyone tell me why?
LVL 1
ntonyAsked:
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.

kretzschmarCommented:
why not use the onClose.event of your MDIChild?
ntonyAuthor Commented:
I have a list with child window so i need to delete the child when it will be closed.
huiyueCommented:

Is the childform really closed in your program.
You can try to write some codes in the two event:OnClose,OnDestroy.
Just like showmessage('c') in onclose;showmessage('d') in onDestroy.
You will find that when you close the Childform,only show "c" ;
When you add "action :=caFree" in OnClose,you will see "d";
So...maybe you will find the right answer.

I guess but not test the following code;
if Message.Msg=WM_Close then begin
     ShowMessage('Child closed');
  end else inherited WndProc(Message);
OWASP: Threats Fundamentals

Learn the top ten threats that are present in modern web-application development and how to protect your business from them.

kretzschmarCommented:
you could notify the mainform in the onClose-event of your MDIChilds instead

may this possible for you?
ntonyAuthor Commented:

huiyue i've used caFree on the child form.

Kretzschmar - i need a simple solution
kretzschmarCommented:
how shows your list?
by classname or by formname?
ntonyAuthor Commented:
is't a stringlist with objects TForm
kretzschmarCommented:
well a sceleton

the main:

unit MDIChild_Notifys_Main_Main_u;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls,
  MDIChild_Notifys_Main_Child;  //uses the childUnit in the Interfacepart

type
  TForm1 = class(TForm)
    Panel1: TPanel;
    Button1: TButton;
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    FFormList : TstringList;
  public
    procedure RemoveFromList(AForm : TForm);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.RemoveFromList(AForm : TForm);
var i : integer;
begin
  i := FFormList.IndexOfObject(AForm);
  if i > -1 then
    FFormList.Delete(i);
  ShowMessage('Child removed.'+#10+'Remaining Childs: '+inttostr(FFormList.Count));
end;


procedure TForm1.FormCreate(Sender: TObject);
begin
  FFormList := TStringList.Create;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  FFormList.Free;
end;

procedure TForm1.Button1Click(Sender: TObject);
var f : Tform2;
begin
  f := Tform2.Create(self);
  FFormList.AddObject('AChild',f);
end;

end.

-----------------------

the child:

unit MDIChild_Notifys_Main_Child;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs;

type
  TForm2 = class(TForm)
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form2: TForm2;

implementation

{$R *.dfm}

uses
  MDIChild_Notifys_Main_Main_u;  //important-> uses in the implementation

procedure TForm2.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  TForm1(Application.MainForm).RemoveFromList(self);
  action := caFree;
end;

end.

----

meikl ;-)

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
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.