开始日期不能超过结束时间的check

1,winform

#region 日历控件

        private void dteStartDate_Validating(object sender, CancelEventArgs e)
        {
            if (!CheckStartDateEndDate(true))
            {
                XtraMessageBox.Show("起始日期不能大于结束日期");
                dteStartDate.Focus();
                e.Cancel = true;
            }
        }

        private void dteEndDate_Validating(object sender, CancelEventArgs e)
        {
            if (!CheckStartDateEndDate(false))
            {
                XtraMessageBox.Show("结束日期不能小于起始日期");
                dteEndDate.Focus();
                e.Cancel = true;
            }
        }

        #endregion

        private bool CheckStartDateEndDate(bool bLeaveFromStartDate)
        {
            if (!(string.IsNullOrEmpty(dteStartDate.Text) || string.IsNullOrEmpty(dteEndDate.Text)))
            {
                if (Convert.ToDateTime(dteStartDate.Text) > Convert.ToDateTime(dteEndDate.Text))
                {
                    if (bLeaveFromStartDate)
                    {
                        return false;
                    }
                    else
                    {
                        return false;
                    }
                }
            }
            return true;
        }

2，web

 

if (txtStartDate.Value==null || !PageValidate.IsDateTime(txtStartDate.Value.ToString()))
      {
        strErr+="请输入正确的开始日期！\\n";  
      }
            if (txtEndDate.Value == null || !PageValidate.IsDateTime(txtEndDate.Value.ToString()))
      {
                strErr += "请输入正确的结束日期！\\n";  
      }

            if(Convert.ToDateTime(txtStartDate.Value.ToString()).CompareTo(Convert.ToDateTime(txtEndDate.Value.ToString()))>0)
            {
                strErr += "开始时间不能大于结束时间！\\n";  
            }

        #region 日期格式判断
        /// <summary>
        /// 日期格式字符串判断
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static bool IsDateTime(string str)
        {
            try
            {
                if (!string.IsNullOrEmpty(str))
                {
                    DateTime.Parse(str);
                    return true;
                }
                else
                {
                    return false;
                }
            }
            catch
            {
                return false;
            }
        } 
        #endregion