private const int WM_NCHITTEST = 0x84;
        private const int HTCLIENT = 0x1;
        private const int HTCAPTION = 0x2;         protected override void WndProc(ref Message m)
        {
            base.WndProc(ref m);
            if (m.Msg == WM_NCHITTEST && this.FormBorderStyle == FormBorderStyle.None)
            {
                Point z = Control.MousePosition;
                if (z != null)
                {
                    Point tmp = this.PointToScreen(new Point());
                    z.X -= tmp.X;
                    z.Y -= tmp.Y;
                }                Padding resizePadding = new Padding(3);
                int result = 0;
                if (z.X < (Left + resizePadding.Left)) result = 10;
                else if (z.X > (Right - resizePadding.Right)) result = 11;                if (z.Y < (Top + resizePadding.Top))
                {
                    switch (result)
                    {
                        case 0:
                            result = 12;
                            break;
                        case 10:
                            result = 13;
                            break;
                        case 11:
                            result = 14;
                            break;
                        default:
                            break;
                    }
                }
                else if (z.Y < (Top + 20))
                {
                    switch (result)
                    {
                        case 0:
                            result = 2;
                            break;
                        default:
                            break;
                    }
                }
                else if (z.Y > (Bottom - resizePadding.Bottom))
                {
                    switch (result)
                    {
                        case 0:
                            result = 15;
                            break;
                        case 10:
                            result = 16;
                            break;
                        case 11:
                            result = 17;
                            break;
                        default:
                            break;
                    }
                }                if (result != 0) m.Result = (IntPtr)result;
            }
        }

解决方案 »

  1.   

    加上移动部分:
            protected override void WndProc(ref Message m)
            {
                base.WndProc(ref m);            #region Move without Form Border            if (m.Msg == WM_NCHITTEST)
                {
                    this.DefWndProc(ref m);
                    if (m.Result.ToInt32() == HTCLIENT)
                        m.Result = new IntPtr(HTCAPTION);
                }            #endregion            #region Resize without Form Border
                
                if (m.Msg == WM_NCHITTEST && this.FormBorderStyle == FormBorderStyle.None)
                {
                    Point z = Control.MousePosition;
                    if (z != null)
                    {
                        Point tmp = this.PointToScreen(new Point());
                        z.X -= tmp.X;
                        z.Y -= tmp.Y;
                    }                Padding resizePadding = new Padding(3);
                    int result = 0;
                    if (z.X < (Left + resizePadding.Left)) result = 10;
                    else if (z.X > (Right - resizePadding.Right)) result = 11;                if (z.Y < (Top + resizePadding.Top))
                    {
                        switch (result)
                        {
                            case 0:
                                result = 12;
                                break;
                            case 10:
                                result = 13;
                                break;
                            case 11:
                                result = 14;
                                break;
                            default:
                                break;
                        }
                    }
                    else if (z.Y < (Top + 20))
                    {
                        switch (result)
                        {
                            case 0:
                                result = 2;
                                break;
                            default:
                                break;
                        }
                    }
                    else if (z.Y > (Bottom - resizePadding.Bottom))
                    {
                        switch (result)
                        {
                            case 0:
                                result = 15;
                                break;
                            case 10:
                                result = 16;
                                break;
                            case 11:
                                result = 17;
                                break;
                            default:
                                break;
                        }
                    }                if (result != 0) m.Result = (IntPtr)result;
                }            #endregion
            }