protected override void OnShown(EventArgs e)
{
base.OnShown(e);
const int WM_SETICON = 0x80;
Bitmap smallIcon = new Bitmap(SystemInformation.SmallIconSize.Width, SystemInformation.SmallIconSize.Height);
SendMessage(this.Handle, WM_SETICON, (IntPtr)0, smallIcon.GetHicon());
SendMessage(this.Handle, WM_SETICON, (IntPtr)1, this.Icon.Handle);
}
[DllImport("user32.dll")]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);