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Asked by bryan7 in Delphi Programming, Free Pascal
Hello,
I'm wondering about the best way to handle this:
I have 2 classes. I create the 1st class, which creates the 2nd class in the Constructor; the 2nd class must access the 1st class in its constructor, but it can't because 1st class is not assigned yet (proven in the code). How would you approach this? I tried AfterConstruction, which didn't work either. I could use a timer or sending a msg to call the 2nd class constructor after the 1st one has finished, but I'd rather use a better way, and within my 1st class (not sending a msg).
What would you do?
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unit Unit7;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs;
type class1 = Class(TObject)
public
Constructor Create;
Destructor Destroy;
End;
type class2 = Class(TObject)
public
Constructor Create;
Destructor Destroy;
End;
type
TForm7 = class(TForm)
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form7: TForm7;
c1: class1;
c2: class2;
implementation
{$R *.dfm}
Constructor class1.Create;
begin
c2 := class2.Create;
end;
Destructor class1.Destroy;
begin
//
end;
Constructor class2.Create;
begin
if Assigned(c1) then showmessage('ok') else showmessage('error');
end;
Destructor class2.Destroy;
begin
//
end;
procedure TForm7.FormCreate(Sender: TObject);
begin
c1 := class1.Create;
end;
end.
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20091111-EE-VQP-92 - Hierarchy / EE_QW_EXPERT_20070906
