Viereck zeichnen OOP

[omata]

Delphi-Quellcode:

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    PaintBox1: TPaintBox;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;


  Tgeo_objects = class
  end;

  Tpunkt = class(Tgeo_objects)
    x,y:integer;
    procedure setx(r:integer);
    procedure sety(r:integer);
  end;

  TLinie = class(Tpunkt)
    p1,p2:TPunkt;
  end;

  TViereck = class(TLinie)
    procedure zeichne;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

var
  MyViereck : TViereck;
  Punkt : TPunkt;

procedure TViereck.zeichne;
begin
  form1.PaintBox1.Canvas.MoveTo(myviereck.x, myviereck.y);
  form1.PaintBox1.Canvas.LineTo(myviereck.x + 100, myviereck.y);
end;


procedure tPunkt.setx(r:integer);
begin
  x:=r;
end;

procedure Tpunkt.sety(r:integer);
begin
  y:=r;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  MyViereck := TViereck.create;
  try
    myviereck.setx(7);
    myviereck.sety(9);
    Myviereck.zeichne;
  finally
    myviereck.Free; 
  end;
end;

end.