Application.MainFormOnTaskbar wird ignoriert (10.4)

[ghubi01]

Hallo,
vielleicht hilft folgendes:

Delphi-Quellcode:

program Project1;

uses
  Vcl.Forms,
  Unit1 in 'Unit1.pas' {Form1};

{$R *.res}

begin
  Application.Initialize;
  //Application.MainFormOnTaskbar := True;
  Application.CreateForm(TForm1, Form1);
  Application.Run;
end.

und Unit:

Delphi-Quellcode:

unit Unit1;

interface

uses
  Winapi.Windows,
  System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.ExtCtrls;

type
  TForm1 = class(TForm)
    BtnBeenden: TButton;
    procedure BtnBeendenClick(Sender: TObject);
    procedure FormShow(Sender: TObject);
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormShow(Sender: TObject);
var
  MyOwner: HWnd;
begin
  MyOwner:=GetWindow(Handle,GW_OWNER);
  ShowWindow(MyOwner,SW_HIDE);
end;

procedure TForm1.BtnBeendenClick(Sender: TObject);
begin
  Close;
end;

end.