Determine whether a window is ‘topmost’

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Determine whether a window is ‘topmost’

function IsWindowTopMost(hWindow: HWND): Boolean;
begin
  Result := (GetWindowLong(hWindow, GWL_EXSTYLE) and WS_EX_TOPMOST) <> 0
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  if isWindowTopMost(FindWindow('notepad', nil)) then
    Label1.Caption := 'Window ist topmost'
  else
    Label1.Caption := 'Window ist not topmost';
end;