protected override void OnPaint(PaintEventArgs e)
{
if (GetStyle(ControlStyles.UserPaint))
{
Message m = new Message();
m.HWnd = Handle;
m.Msg = 0x0318; // WM_PRINTCLIENT;
m.WParam = e.Graphics.GetHdc();
m.LParam = (IntPtr)4; // PRF_CLIENT;
DefWndProc(ref m);
e.Graphics.ReleaseHdc(m.WParam);
}
base.OnPaint(e);
}