变Enter键为Tab键 实现焦点转移

 /// <summary>
    /// 窗体控件控制相关的方法
    /// </summary>
    public class ControlTools
    {
        private Form frm;

        public ControlTools(Form frm)
        {
            this.frm = frm;
        }

        /// <summary>
        /// 窗体上所有子控件的回车设成Tab
        /// </summary>
        public void EnterToTab()
        {
            frm.KeyPreview = true;

            frm.KeyPress += new KeyPressEventHandler(frm_KeyPress);
        }
        /// <summary>
        /// 注册窗体的KeyPress事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void frm_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == (char)Keys.Enter)
            {
                frm.SelectNextControl(frm.ActiveControl, true, true, true, true);
            }
        }

        /// <summary>
        /// 把某一个控件的所有子控件(TextBox ComboBox)的回车设成Tab
        /// </summary>
        /// <param name="groupControl">容器控件</param>
        public void EnterToTab(Control groupControl)
        {
            foreach (Control control in groupControl.Controls)
            {
                if (control is TextBox || control is ComboBox)
                    control.KeyPress += new KeyPressEventHandler(control_KeyPress);
            }
        }

        /// <summary>
        /// 注册控件的KeyPress事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void control_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == 13)
            {
                SendKeys.Send("{Tab}");
                e.Handled = false;
            }
        }

    }