IMemoChangeEvent = interface
  ['{DCFE64D2-9BA8-4949-9BB1-F5CD672E51A2}']
    procedure SetText(const Value: string);
    function GetText: String;
    property Text: string read GetText write SetText;
  end;

  TMemoChangeEvent = class(TInterfacedObject, IMemoChangeEvent)
  private
    FText: string;
    procedure SetText(const Value: string);
    function GetText: String;
  public
    property Text: string read GetText write SetText;
  end;

function GetMemoEvent: IMemoChangeEvent;
begin
  Result:= TMemoChangeEvent.Create;
end;

procedure TfrmMain.Memo1Change(Sender: TObject);
var
  LEvent: IMemoChangeEvent;
begin
  LEvent := GetMemoEvent;//取得接口
  LEvent.Text := Memo1.Lines.Text;//为接口赋值
  GlobalEventBus.Post(LEvent);//发布接口实例
end;

    [Subscribe]
    procedure OnMemoChange(AEvent: IMemoChangeEvent);

procedure TfrmSecond.OnMemoChange(AEvent: IMemoChangeEvent);
begin
  MemoObserver.Lines.Text := AEvent.Text;
end;

procedure TfrmSecond.FormCreate(Sender: TObject);
begin
   GlobalEventBus.RegisterSubscriberForEvents(Self);//一般情况下，我们都是在对象建立时注册
end;

procedure TfrmSecond.FormDestroy(Sender: TObject);
begin
   GlobalEventBus.UnregisterForEvents(Self);//取消注册
end;