COM ActiveX   3GL   4GL

. , .

, . Delphi, . . ? . , :
- , ;
- , Delphi ActiveX;
- , ; - ;
- , , Delphi, .
, , . . , . , :
- , ; - , ;
- ;
- (, -);
- ( ):
 ;
 () ;
 , ;
 ;
 Delphi;
 . .

, , VCL Delphi. , (. 6). . 2.9.
2.9. VCL



TObject

, , . TObject , , ,

TComponent


TGraphicControl

, . . .

TWinControl

, .

TCustomControl

TWinControl (). Paint.

TCustomClassName

, published, . . , -, . , ClassName

TComponentName

-, VCL Delphi. , - Delphi,


, -, Delphi .

, - . . () Delphi, (Component Expert). Delphi Component/New Component (/ ). , . 2.13.

 2.13
. 2.13.
. , Ancestor type - . VCL. , , TButton. TButton. Class Name . TMyButton. , Delphi - ( TButtoni). Palette Page , . , Delphi samples. Unit file name Search path Delphi , . . , . 2.14.

 2.14
. 2.14.
, Delphi . 2.7.

2.7
unit MyButton;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls; type
TMyButton = class(TButton)
private
{ Private declarations }
protected
{ Protected declarations } public
{ Public declarations } published
{ Published declarations } end;
procedure Register; implementation procedure Register; begin
RegisterComponents('Samples', [TMyButton]); end;
end.


, . , . , , , TButton. (. "- " 1). . .
: (static), (virtual), (dynamic) - (message). , .

Delphi. Delphi , Delphi . , (overload).
, , .
:
type
TComponent = class
procedure MyProcedure;
end;

, MyProcedure . TObject class. , TObject.

, , , Delphi ( ). , Delphi (Virtual Method Table), . , . , , , .
:
type
TComponent = class
procedure MyProcedure; virtual;
end;

MyProcedure - .

, . - . , -, (Dynamic Method Table), , . , ( ). , , . . .
:
type
TComponent = class
procedure MyProcedure; dynamic;
end;

-
- , . , - Windows. -:
type
TComponent = class
procedure MyProcedure(Var A: TMessage); message wm_MessageWindows;
end;

message ( wmjfessagewindows), Windows, MyProcedure.
(overriden) (abstract).

() () . , . :
type
TComponentChild = class (TComponentParent)
procedure MyProcVirtual; override;
procedure MyProcDynamic; override;
end;

override . ( ).
virtual dynamic override, .
- .

. , , . -. :
procedure MyProcedure; virtual; abstract;


, . . , . EAbstractError.

, .

  COM ActiveX   3GL   4GL

, , Sequence diagram - - , . .
{DATA}




 18.01.2021 - 11:33: - Personalias -> WHO IS WHO - - _.
18.01.2021 - 09:05: , - War, Politics and Science -> . - _.
18.01.2021 - 08:21: , , - Upbringing, Inlightening, Education -> - _.
18.01.2021 - 07:41: , , - Upbringing, Inlightening, Education -> - _.
17.01.2021 - 17:59: , - War, Politics and Science -> - _.
17.01.2021 - 16:46: , , - Upbringing, Inlightening, Education -> - _.
17.01.2021 - 16:00: - Ecology -> - _.
16.01.2021 - 08:30: - Conscience -> . ? - _.
15.01.2021 - 09:03: , - War, Politics and Science -> - _.
15.01.2021 - 09:03: , , - Upbringing, Inlightening, Education -> - _.
15.01.2021 - 08:20: - Theorizing and Mathematical Design -> - - _.
15.01.2021 - 08:19: , , - Upbringing, Inlightening, Education -> - _.
Bourabai Research -  XXI Bourabai Research Institution