winform如何让窗体不显示Icon但在任务栏中显示Icon

        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);