Canguro.Controller.Grid.JointDOFControl.JointDOFControl_KeyDown C# (CSharp) Метод

        private void JointDOFControl_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Right || e.KeyCode == Keys.Tab)
            {
                nextFocus(sender);
                e.Handled = true;
            }
            else if (e.KeyCode == Keys.Left)
            {
                previousFocus(sender);
                e.Handled = true;
            }
            else if (e.KeyCode == Keys.Enter)
            {
                editingControl.DropDown.Close(ToolStripDropDownCloseReason.ItemClicked);
                e.Handled = true;
            }
            else if (sender is TextBox)
            {
                Keys k = e.KeyCode;
                bool beep = false;

                if (k != Keys.Back)
                    beep = !e.Alt && !e.Control && (k >= Keys.A && k <= Keys.Z);

                if (k == Keys.OemPeriod)
                    if (((TextBox)sender).Text.Contains("."))
                        beep = true;

                if (beep)
                {
                    Canguro.Utility.NativeMethods.MessageBeep(Canguro.Utility.NativeMethods.MB_ICONEXCLAMATION);
                    e.SuppressKeyPress = true;
                }
            }
        }