WinAPI: GetTopWindow - 获取指定窗口的子窗口中最顶层的窗口句柄

//声明:
GetTopWindow(
hWnd: HWND; {指定的窗口句柄}
): HWND;      {失败返回0; 成功返回最顶层的子窗口句柄}

var
h1,h2: HWND;
begin
h1 := GetTopWindow(GetDesktopWindow);
h2 := GetWindow(GetDesktopWindow, GW_CHILD);
ShowMessage(Format('%d,%d',[h1,h2])); {132540,132540}
end;