Enter键转Tab键

        /// <summary>
        /// 判断键盘按下的键
        /// </summary>
        protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
        {   
            //判断键盘按下的键。如果等于“enter”，则send一个“{tab}”
            if (keyData == Keys.Enter && !txtLate.Focused && !btnAdd.Focused &&!btnUpdate.Focused)
            {
                System.Windows.Forms.SendKeys.Send("{tab}");
                return true;
            }
            //继续原来base.ProcessCmdKey中的处理
            return base.ProcessCmdKey(ref msg, keyData);
        }