#region 無邊框拖動效果    [DllImport("user32.dll")]//拖動無窗體的控件    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;    private void Start_MouseDown(object sender, MouseEventArgs e)    {      //拖動窗體      ReleaseCapture();      SendMessage(this.Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0);    }    #endregion