让普通控件拥有左键移动窗体的功能

如题，代码如下：

        /// <summary>设置可以鼠标左键让窗体移动的控件
        /// </summary>
        /// <param name="form">待移动的窗体，通常是设置了FormBorderStyle = FormBorderStyle.None的窗体</param>
        /// <param name="control">能控制窗体左键移动的控件</param>
        public static void SetMoveFormControl(Form form, Control control)
        {
            control.MouseDown += (s, e) =>
            {
                ReleaseCapture();
                SendMessageA((int)form.Handle, 0xa1, 2, 0);
            };
        }
        [DllImport("user32.dll")]
        private static extern int ReleaseCapture();
        [DllImport("user32.dll")]
        private static extern int SendMessageA(int hwnd, int wMsg, int wParam, int lParam);