常用验证方法

 /// <summary>         /// 验证正整数         /// </summary>         /// <param name="str"></param>         /// <returns></returns>         public static string zhengshu(String str)         {             string flag = string.Empty;

            Regex r = new Regex(@"^d+$");             if (r.IsMatch(str))             {                 flag = "OK";             }             else             {                 flag = "只能输入0和正整数！";             }

            return flag;         }

        /// <summary>         /// 验证小数         /// </summary>         /// <param name="str"></param>         /// <returns></returns>         public static string xiaoshu(String str)         {             string flag = string.Empty;

            Regex r = new Regex(@"^0$|^(-)?((0)?.d+)$|^(-)?([1-9]d*(.d+)?)$");             if (r.IsMatch(str))             {                 flag = "OK";             }             else             {                 flag = "只能整数和小数！";             }

            return flag;         }

        #region 截取固定长度的字符串         /// <summary>         /// 处理字符串长度 如果长度大于输入长度截取         /// </summary>         /// <param name="info"></param>         /// <param name="length"></param>         /// <returns></returns>         public static string getSafeStr2(string info, int length = 15)         {             if (info == string.Empty)                 return "";

            string retInfo = info.Replace("'", "''");

            if (info.Length > length)             {                 retInfo = info.Substring(0, length)+"...";             }             return retInfo;         }         #endregion

        /// <summary>         /// 验证日期格式         /// </summary>         /// <param name="str"></param>         /// <returns></returns>         public static string riqi(String str)         {             string flag = string.Empty;

            Regex r = new Regex(@"^[1-2]{1}d{3}[0-1]{1}d{1}[0-3]{1}d{1}$");             if (r.IsMatch(str))             {                 flag = "OK";             }             else             {                 flag = "日期格式有误（yyyymmdd）！";             }

            return flag;         }

        /// <summary>         /// 邮箱格式         /// </summary>         /// <param name="str"></param>         /// <returns></returns>         public static string EmailRegex(String str)         {             string flag = string.Empty;

            Regex r = new Regex(@"^[a-zA-Z0-9_-]+@[a-zA-Z0-9_-]+(.[a-zA-Z0-9_-]+)+$");             if (r.IsMatch(str))             {                 flag = "OK";             }             else             {                 flag = "邮箱格式有误（yyyymmdd）！";             }

            return flag;         }

        /// <summary>         /// 电话验证         /// </summary>         /// <param name="str"></param>         /// <returns></returns>         public static string PhoneRegex(String str)         {             string flag = string.Empty;

            Regex r = new Regex(@"^((d{11})|^((d{7,8})|(d{4}|d{3})-(d{7,8})|(d{4}|d{3})-(d{7,8})-(d{4}|d{3}|d{2}|d{1})|(d{7,8})-(d{4}|d{3}|d{2}|d{1}))$)");             if (r.IsMatch(str))             {                 flag = "OK";             }             else             {                 flag = "电话格式有误（yyyymmdd）！";             }

            return flag;         }

        /// <summary>         /// 四位数字         /// </summary>         /// <param name="str"></param>         /// <returns></returns>         public static string SZRegex(String str)         {             string flag = string.Empty;

            Regex r = new Regex(@"^d{4}$");             if (r.IsMatch(str))             {                 flag = "OK";             }             else             {                 flag = "数字格式有误（yyyymmdd）！";             }

            return flag;         }