delphi中的面向对象思想

ugg

unit Unit2;

interface
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;
type
  mammal=class    //哺乳动物
  private
   ear:string; //  耳朵
   eye:string;  // 眼睛
   mouth:string; //嘴巴
   nose:string;  //鼻子
  public
  procedure sound;virtual;abstract;
end;
//--------------------------------------------------------------------
type               //猫
  cat=class(mammal)
  private
  public
  procedure paw;virtual;abstract;
  procedure sound;override;
end;

type
  whitecat=class(cat)
  private
  public
  procedure paw;override;
end;

type
  blackcat=class(cat)
  private
  public
  procedure paw;override;
end;
//------------------------------------------
type
  dog=class(mammal)
  private
  public
  procedure sound;override;
  procedure watching;
end;

implementation

procedure cat.sound;
begin
  showmessage('catsound');
end;
procedure whitecat.paw;
begin
  showmessage('whitecatpaw');
end;
procedure blackcat.paw;
begin
  showmessage('blackcatpaw');
end;
procedure dog.sound;
begin
  showmessage('dogsound');
end;
procedure dog.watching;
begin
  showmessage('dogwatching');
end;
end.

ugg

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
   Button1: TButton;
   Button2: TButton;
   Button3: TButton;
   Button4: TButton;
   Button5: TButton;
   procedure Button1Click(Sender: TObject);
   procedure Button2Click(Sender: TObject);
  private
   { Private declarations }
  public
   { Public declarations }
  end;

var
  Form1: TForm1;

implementation
uses unit2;

{$R *.dfm}
//procedure mymammal(my:mammal);
//begin
// my.sound;
//end;

procedure TForm1.Button1Click(Sender: TObject);
var
  ocat:cat;
begin
  ocat:=cat.Create;
  ocat.sound;
  ocat.Free;
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  ocat:whitecat;
begin
  ocat:=whitecat.Create;
  ocat.paw;
  ocat.Free;
end;

end.

ugg

实际上,DELPHI都可以实现C++的一些功能,很多人认为它是一种类似于VB的RAD思想的语言
其实不然,它完全可以实现OOP思想的,呵呵