示例：中介者接口 说明： （1）、定义 用一个中介对象来封装一系列的对象交互。中介者使各对象不需要显式地相互引用，从而使其耦合松散，而且可以独立地改变它们之间的交互。 （2）、结构 中介者 Mediator(中介者)：中介者定义一个接口用于与各同事（Colleague）对象通信。 ConcreteMediator(具体中介者)：具体中介者通过协调各同事对象实现协作行为。了解并维护它的各个同事。 同事 Colleagueclass(同事类)：每一个同事类都知道它的中介者对象。每一个同事对象在需与其他的同事通信的时候，与它的中介者通信。 代码： unit uMediator; interface uses SysUtils, Dialogs; type TMediator = class; TColleague = class private FMediator: TMediator; public constructor Create(AMediator: TMediator); //--- procedure Notify(); end; TConcreteColleague1 = class(TColleague) private FValue: Integer; procedure SetValue(const Value: Integer); public property Value: Integer read FValue write SetValue; end; TConcreteColleague2 = class(TColleague) private FValue: Integer; procedure SetValue(const Value: Integer); public property Value: Integer read FValue write SetValue; end; TMediator = class public procedure Changed(AColleague: TColleague); virtual; abstract; end; TConcreteMediator = class(TMediator) private FColleague1: TConcreteColleague1; FColleague2: TConcreteColleague1; public constructor Create; destructor Destroy; override; //--- procedure Changed(AColleague: TColleague); override; procedure Calc; end; procedure Test; implementation procedure Test; var AMediator: TConcreteMediator; begin AMediator := TConcreteMediator.Create; AMediator.Calc; AMediator.Free; end; constructor TColleague.Create(AMediator: TMediator); begin FMediator := AMediator; end; procedure TColleague.Notify; begin FMediator.Changed(self); end; procedure TConcreteColleague1.SetValue(const Value: Integer); begin FValue := Value; //--- self.Notify; end; procedure TConcreteColleague2.SetValue(const Value: Integer); begin FValue := Value; //--- self.Notify; end; procedure TConcreteMediator.Calc; begin FColleague1.Value := 1; end; procedure TConcreteMediator.Changed(AColleague: TColleague); begin if AColleague = FColleague1 then FColleague2.Value := FColleague1.Value + 2 else if AColleague = FColleague2 then ShowMessage(IntToStr(FColleague2.Value)); end; constructor TConcreteMediator.Create; begin inherited; //--- FColleague1 := TConcreteColleague1.Create(self); FColleague2 := TConcreteColleague1.Create(self); end; destructor TConcreteMediator.Destroy; //--- procedure _Free(AColleague: TColleague); begin if AColleague <> nil then AColleague.Free; end; begin _Free(FColleague1); _Free(FColleague2); //--- inherited; end; end.
