public static extern IntPtr EnumWindows(DllImportManeger.CallBack lpfn, IntPtr lParam);
 public static extern IntPtr EnumChildWindows(IntPtr hWndParent, DllImportManeger.CallBack lpfn, IntPtr lParam);
 public static extern IntPtr EnumThreadWindows(IntPtr dwThreadId, DllImportManeger.CallBack lpfn, IntPtr lParam);