适配器模式的主要意图是对现有类的接口进行转换，以满足目标类的需求。其次，可以给目标类的接口添加新的行为（主要指方法）。这一点容易与装饰模式混淆。从意图方面来看，装饰模式不改变（通常指增加）接口中的行为（主要指方法），而是在原有行为（主要指方法）的基础上添加新的功能；从类结构方面来看，装饰模式中的装饰者既继承又组合被装饰者。类适配器同时继承现有类和目标类，对象适配器继承目标类组合现有类。
{《HeadFirst设计模式》之适配器模式 }{ 现有类 }{ 编译工具：Delphi7.0 }{ E-Mail ：guzh-0417@163.com } unit uAdaptee;interfacetype TTurkey = class(TObject) public procedure Gobble; virtual; abstract; procedure Fly; virtual; abstract; end; TWildTurkey = class(TTurkey) public procedure Gobble; override; procedure Fly; override; end;implementation{ TWildTurkey }procedure TWildTurkey.Fly;begin Writeln(‘I‘‘m flying a short distance.‘);end;procedure TWildTurkey.Gobble;begin Writeln(‘Gobble gobble.‘);end;end.
{《HeadFirst设计模式》之适配器模式 }{ 目标类 }{ 编译工具：Delphi7.0 }{ E-Mail ：guzh-0417@163.com }unit uTarget;interfacetype TDuck = class(TObject) public procedure Quack; virtual; abstract; procedure Fly; virtual; abstract; end; TMallarDuck = class(TDuck) public procedure Quack; override; procedure Fly; override; end;implementation{ TMallarDuck }procedure TMallarDuck.Fly;begin Writeln(‘I‘‘m flying.‘);end;procedure TMallarDuck.Quack;begin Writeln(‘Quack.‘);end;end.
{《HeadFirst设计模式》之适配器模式 }{ 适配器，转换现有类的接口 }{ 编译工具：Delphi7.0 }{ E-Mail ：guzh-0417@163.com }unit uAdapter;interfaceuses uTarget, uAdaptee;type TTurkeyAdapter = class(TDuck) private FTurkey: TTurkey; public constructor Create(aTurkey: TTurkey); procedure Quack; override; procedure Fly; override; end;implementation{ TTurkeyAdapter }constructor TTurkeyAdapter.Create(aTurkey: TTurkey);begin FTurkey := aTurkey;end;procedure TTurkeyAdapter.Fly;var i: Integer;begin for i := 0 to 4 do begin FTurkey.Fly; end;end;procedure TTurkeyAdapter.Quack;begin FTurkey.Gobble;end;end.
{《HeadFirst设计模式》之适配器模式 }{ 客户端 }{ 编译工具：Delphi7.0 }{ E-Mail ：guzh-0417@163.com }program pDuckTestDrive;{$APPTYPE CONSOLE}uses SysUtils, uAdaptee in ‘uAdaptee.pas‘, uAdapter in ‘uAdapter.pas‘, uTarget in ‘uTarget.pas‘; var Duck : TMallarDuck; Turkey: TWildTurkey; TurkeyAdapter: TTurkeyAdapter;procedure TestDuck(aDuck: TDuck);begin aDuck.Quack; aDuck.Fly;end;begin Duck := TMallarDuck.Create; Turkey := TWildTurkey.Create; TurkeyAdapter := TTurkeyAdapter.Create(Turkey); Writeln(‘The turkey says:‘); Turkey.Gobble; Turkey.Fly; Writeln; Writeln(‘The duck says:‘); TestDuck(Duck); Writeln; Writeln(‘The turkeyAdapter says:‘); TestDuck(TurkeyAdapter); FreeAndNil(Duck); FreeAndNil(Turkey); FreeAndNil(TurkeyAdapter); Readln;end.
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Delphi 设计模式：《HeadFirst设计模式》Delphi7代码---适配器模式之TurkeyAdapter[转]
原文：http://www.cnblogs.com/0x2D-0x22/p/4076307.html