无边框窗体 移动

1:在Program中添加以下代码，需要引用命名空间
[DllImport("user32.dll")]
        public static extern bool ReleaseCapture();
        [DllImport("user32.dll")]
        public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);

        public const int WM_SYSCOMMAND = 0x0112;
        public const int SC_MOVE = 0xF010;
        public const int HTCAPTION = 0x0002;

2:在无边框窗体中写入以下方法：
private void MoveEventHandler(Control ctrl)
        {
            if (ctrl.Controls.Count > 0)
            {
                ctrl.MouseDown += new MouseEventHandler(FormLogin_MouseDown);
                foreach (Control c in ctrl.Controls)
                {
                    MoveEventHandler(c);
                }
            }
            else
            {
                ctrl.MouseDown += new MouseEventHandler(FormLogin_MouseDown);
            }
        }

        public FormLogin()
        {
            InitializeComponent();