uinterface.pas

观察者模式delphi实例实现,同时注意软件的设计

unit uInterface;

interface
uses
    Windows, Messages, SysUtils, Graphics, Forms, Dialogs, Controls, classes;

type
    //属性描述
    TPhotoProp = record
        Name:string;
        Desc:string;
        Data:TDateTime;
        Size:Integer;
    end;
    
    //通知接口
    //由photoMgr发送有关照片变更的消息通知界面组件。
    //通知的内容
    //增加，删除，刷新，属性变化
    IPhotoNotify = interface
        function SelPhoto(const photoID:Integer):Boolean;
        function NewPhoto(const photoID:Integer):Boolean;
        function DelPhoto(const photoID:Integer):Boolean;
        function Refresh():Boolean;
        function PropChange(const photoID:Integer):Boolean;
    end;

{------------------------------------------------------------------------------}
    //实现PhotoMgr接口
    //由PhotoMgr类来实现
    IPhotoMgr = interface
        function GetPhotoCount(var Count:Integer):Boolean;
        function GetPhotoID(const idx:Integer; var PhotoID:Integer):Boolean;
        function GetSelPhotoID(var PhotoID:Integer):Boolean;
        function GetPhotoPorp(const photoID:Integer;var PhotoProp:TPhotoProp):Boolean;
        function GetBmp(const PhotoID:Integer;var bmp:TBitmap):Boolean;
    end;

implementation

end.