//命令的接受者

unit uReceiveObject;

interface

type

  TLight = class(TObject)

  public

    procedure Open;

    procedure Off;

  end;

  TGarageDoor = class(TObject)

  public

    procedure Up;

    procedure Down;

    procedure Stop;

    procedure LightOn;

    procedure LightOff;

  end;

implementation

{ TLight }

procedure TLight.Off;

begin

  Writeln('');

end;

procedure TLight.Open;

begin

  Writeln('Light is On.');

end;

{ TGarageDoor }

procedure TGarageDoor.Down;

begin

  Writeln('');

end;

procedure TGarageDoor.LightOff;

begin

  Writeln('');

end;

procedure TGarageDoor.LightOn;

begin

  Writeln('');

end;

procedure TGarageDoor.Stop;

begin

  Writeln('');

end;

procedure TGarageDoor.Up;

begin

  Writeln('GarageDoor is Open.');

end;

end.

 

//命令对象

unit uCommandObject;

interface

uses

  uReceiveObject;

type

  TCommand = class(TObject)

  public

    procedure Execute; virtual; abstract;

  end;

  TLightOnCommand = class(TCommand)

  private

    FLight: TLight;

  public

    constructor Create(aLight: TLight);

    procedure Execute; override;

  end;

  TGarageDoorOpenCommand = class(Tcommand)

  private

    FGarageDoor: TGarageDoor;

  public

    constructor Create(aGarageDoor: TGarageDoor);

    procedure Execute; override;

  end;

implementation

{ TLightOnCommand }

constructor TLightOnCommand.Create(aLight: TLight);

begin

  FLight := aLight;

end;

procedure TLightOnCommand.Execute;

begin

  FLight.Open;

end;

{ TGarageDoorOpenCommand }

constructor TGarageDoorOpenCommand.Create(aGarageDoor: TGarageDoor);

begin

  FGarageDoor := aGarageDoor;

end;

procedure TGarageDoorOpenCommand.Execute;

begin

  FGarageDoor.Up;

end;

end.

 

//命令的请求者即发出者

unit uSimpleRemoteControl;

interface

uses

  uCommandObject;

type

  TSimpleRemoteControl = class(TObject)

  private

    FSlot: TCommand;

  public

    procedure SetCommand(aCommand: TCommand);

    procedure ButtonWasPressed;

  end;

implementation

{ TSimpleRemoteControl }

procedure TSimpleRemoteControl.ButtonWasPressed;

begin

  FSlot.Execute;

end;

procedure TSimpleRemoteControl.SetCommand(aCommand: TCommand);

begin

  FSlot := aCommand;

end;

end.

 

//客户端代码

program pSimpleRemoteControlTest;

{$APPTYPE CONSOLE}

uses

  uSimpleRemoteControl in 'uSimpleRemoteControl.pas',

  uCommandObject in 'uCommandObject.pas',

  uReceiveObject in 'uReceiveObject.pas';

var

  Remote: TSimpleRemoteControl;

  Light: TLight;

  GarageDoor: TGarageDoor;

  LightOnCommand: TCommand;

  GarageDoorOpenCommand: TCommand;

  

begin

  {创建命令的发出者}

  Remote := TSimpleRemoteControl.Create;

  {创建命令的接收者}

  Light := TLight.Create;

  GarageDoor := TGarageDoor.Create;

  {创建具体的命令对象}

  LightOnCommand := TLightOnCommand.Create(Light);

  GarageDoorOpenCommand := TGarageDoorOpenCommand.Create(GarageDoor);

  {加载命令并执行}

  Remote.SetCommand(LightOnCommand);

  Remote.ButtonWasPressed;

  Remote.SetCommand(GarageDoorOpenCommand);

  Remote.ButtonWasPressed;

  Remote.Free;

  Light.Free;

  GarageDoor.Free;

  LightOnCommand.Free;

  GarageDoorOpenCommand.Free;

  

  Readln;

end.

//运行结果