Delphi 接口托管实现

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

  IMyInterface = interface(IUnknown)
   procedure ShowString(s: string);
  end;

  TMyClass = class(TInterfacedObject, IMyInterface)
  public
    procedure ShowString(s: string);
  end;

  TSecondClass = class(TInterfacedObject, IMyInterface)
  protected
    myInterface: IMyInterface;
  protected
    property my: IMyInterface read myInterface implements IMyInterface;
  public
    constructor Create(AOwner: TObject); overload;
  end;


var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
  myclass: TMyClass;
  mySecondclass: TSecondClass;
begin
  myclass := TMyClass.Create;
  mySecondclass := TSecondClass.Create(nil);
  myclass.ShowString('sss');
  mySecondclass.my.ShowString('aaa');
  myclass.Free;
  mySecondclass.Free;
end;

{ TMyClass }

procedure TMyClass.ShowString(s: string);
begin
  ShowMessage(s);
end;

{ TSecondClass }

constructor TSecondClass.Create(AOwner: TObject);
begin
  myInterface := TMyClass.Create;
end;

end.