将控件转换成圆形

有点儿鸡肋的感觉

        [System.Runtime.InteropServices.DllImport("gdi32")]
        private static extern IntPtr BeginPath(IntPtr hdc);
        [System.Runtime.InteropServices.DllImport("gdi32")]
        private static extern int SetBkMode(IntPtr hdc, int nBkMode);
        const int TRANSPARENT = 1;
        [System.Runtime.InteropServices.DllImport("gdi32")]
        private static extern IntPtr EndPath(IntPtr hdc);
        [System.Runtime.InteropServices.DllImport("gdi32")]
        private static extern IntPtr PathToRegion(IntPtr hdc);
        [System.Runtime.InteropServices.DllImport("gdi32")]
        private static extern int Ellipse(IntPtr hdc, int x1, int y1, int x2, int y2);
        [System.Runtime.InteropServices.DllImport("user32")]
        private static extern IntPtr SetWindowRgn(IntPtr hwnd, IntPtr hRgn, bool bRedraw);
        [System.Runtime.InteropServices.DllImport("user32")]
        private static extern IntPtr GetDC(IntPtr hwnd);
        /// <summary>
        /// 将控件转为圆形
        /// </summary>
        /// <param name="control">控件名</param> 
        public static void MakeControlToCircle(Control[] control)
        {
            IntPtr dc;
            IntPtr region;
            for (int i = 0; i < control.Length; i++)
            {
                dc = GetDC(control[i].Handle);
                BeginPath(dc);
                SetBkMode(dc, TRANSPARENT);
                Ellipse(dc, 0, 0, control[i].Width - 3, control[i].Height - 2);
                EndPath(dc);
                region = PathToRegion(dc);
                SetWindowRgn(control[i].Handle, region, false);
            }
        }