怎么模拟系统按扭？

Question

procedure TForm1.Button1Click(Sender: TObject);
begin
  TrackPopupMenuEx(GetSystemMenu(Handle, False),
    TPM_VERTICAL, Mouse.CursorPos.X, Mouse.CursorPos.Y, Handle, nil);
end;

Answer 1

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
    procedure WMCOMMAND(var Msg: TWMCOMMAND); message WM_COMMAND;
  public
    { Public declarations }
  end;var
  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);
begin
  TrackPopupMenuEx(GetSystemMenu(Handle, False),
    TPM_VERTICAL, Mouse.CursorPos.X, Mouse.CursorPos.Y, Handle, nil);
end;procedure TForm1.WMCOMMAND(var Msg: TWMCOMMAND);
begin
  inherited;
  Perform(WM_SYSCOMMAND, Msg.ItemID, 0);
end;

Answer 2

GetSystemMenu()//得到窗体系统菜单句柄
TrackPopupMenuEx()//弹出菜单
Mouse//当前鼠标对象

Answer 3

我的Form是bsNone类型的，用了上面几位大侠的招式，还是没有显示出来，
请大家多帮忙！

Answer 4

//前提怎么现在才说?procedure TForm1.Button1Click(Sender: TObject);
begin
  TrackPopupMenuEx(GetSystemMenu(Application.Handle, False),
//                               ~~~~~~~~~~~~~~~~~~
    TPM_VERTICAL, Mouse.CursorPos.X, Mouse.CursorPos.Y, Handle, nil);
end;