c#驗證字符串是否是身份證、email、正整數的方法

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Text.RegularExpressions;

namespace Logistics
{
    /// <summary>
    /// 通用驗證類
    /// </summary>
    class DataValidate
    {
        /// <summary>
        /// 驗證正整數
        /// </summary>
        /// <param name="txt"></param>
        /// <returns></returns>
        public static bool IsInteger(string txt)
        {
            Regex objReg = new Regex(@"^[1-9]\d*$");
            return objReg.IsMatch(txt);
        }
        /// <summary>
        /// 驗證是否是Email
        /// </summary>
        /// <param name="txt"></param>
        /// <returns></returns>
        public static bool IsEmail(string txt)
        {
            Regex objReg = new Regex(@"\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*");
            return objReg.IsMatch(txt);
        }
        /// <summary>
        /// 驗證身份證
        /// </summary>
        /// <param name="txt"></param>
        /// <returns></returns>
        public static bool IsIdentityCard(string txt)
        {
            Regex objReg = new Regex(@"^(\d{15}$|^\d{18}$|^\d{17}(\d|X|x))$");
            return objReg.IsMatch(txt);
        }
    }
}