Delphi 设计模式：《HeadFirst设计模式》Delphi代码

一、一个叫声接口和几只鸭子
1、从一个叫声接口开始
{《HeadFirst设计模式》Delphi代码之模式小结 }
{ 一个叫声接口 }
{ 编译工具：Delphi2010 for win32 }
{ E-Mail ：xshlife@163.com }

unit uQuackable;

interface

type
IQuackable = interface(IInterface)
procedure Quack;
end;

implementation

end.

2、几只鸭子实现了该叫声接口。
{《HeadFirst设计模式》Delphi代码之模式小结 }
{ 几只鸭子实现了声接口 }
{ 编译工具：Delphi2010 for win32 }
{ E-Mail ：xshlife@163.com }

unit uDuck;

interface

uses
uQuackable;

type
TMallardDuck = class(TInterfacedObject, IQuackable)
public
procedure Quack;
end;

TRedHeadDuck = class(TInterfacedObject, IQuackable)
public
procedure Quack;
end;

TDuckCall = class(TInterfacedObject, IQuackable)
public
procedure Quack;
end;

TRubberDuck = class(TInterfacedObject, IQuackable)
public
procedure Quack;
end;

implementation

{ TMallardDuck }

procedure TMallardDuck.Quack;
begin
Writeln('Quack');
end;

{ TRedHeadDuck }

procedure TRedHeadDuck.Quack;
begin
Writeln('Quack');
end;

{ TDuckCall }

procedure TDuckCall.Quack;
begin
Writeln('Kwak');
end;

{ TRubberDuck }

procedure TRubberDuck.Quack;
begin
Writeln('Squeak');
end;

end.

3、叫声接口为鸭鸣器提供服务。叫声接口与鸭鸣器的关系比与它的实现类更密切。
{《HeadFirst设计模式》Delphi代码之模式小结 }
{ 鸭鸣模拟器 }
{ 编译工具：Delphi2010 for win32 }
{ E-Mail ：xshlife@163.com }

unit uDuckSimulator;

interface

uses
uQuackable, uDuck;

type
TDuckSimulator = class(TObject)
private
procedure Simulate(aDuck: IQuackable); overload;
public
procedure Simulate; overload;
end;

implementation

{ TDuck