校验身份证号

public static bool isCardId(string cardId)
        {
            if (cardId.Length == 18)
            {
                return isCardId18(cardId);
            }
            else if (cardId.Length == 15)
            {
                return isCardId15(cardId);
            }
            else
            {
                return false;
            }
        }

校验18位身份证号

public static bool isCardId18(string cardId)
        {
            long n = 0;
            if (long.TryParse(cardId.Remove(17), out n) == false || n < Math.Pow(10, 16) 
            || long.TryParse(cardId.Replace('x', '0').Replace('X', '0'), out n) == false)
            {
                return false;
                //数字验证
            }
            //地址验证
            if (!areaInfo.ContainsKey(cardId.Remove(6)))
                return false;
            string birth = cardId.Substring(6, 8).Insert(6, "-").Insert(4, "-");
            DateTime time = new DateTime();
            if (DateTime.TryParse(birth, out time) == false)
            {
                return false;
                //生日验证
            }
            string[] arrVarifyCode = ("1,0,x,9,8,7,6,5,4,3,2").Split(',');
            string[] Wi = ("7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2").Split(',');
            char[] Ai = cardId.Remove(17).ToCharArray();
            int sum = 0;
            for (int i = 0; i < 17; i++)
            {
                sum += int.Parse(Wi[i]) * int.Parse(Ai[i].ToString());
            }
            int y = -1;
            Math.DivRem(sum, 11, out y);
            if (arrVarifyCode[y] != cardId.Substring(17, 1).ToLower())
            {
                return false;
                //校验码验证
            }
            return true;
            //符合GB11643-1999标准
        }

校验15位身份证号

public static bool isCardId15(string cardId)
        {
            long n = 0;
            if (long.TryParse(cardId, out n) == false || n < Math.Pow(10, 14))
            {
                return false;
                //数字验证
            }
            //地址验证
            if (!areaInfo.ContainsKey(cardId.Remove(6)))
                return false;
            string birth = cardId.Substring(6, 6).Insert(4, "-").Insert(2, "-");
            DateTime time = new DateTime();
            if (DateTime.TryParse(birth, out time) == false)
            {
                return false;
                //生日验证
            }
            return true;
            //符合15位身份证标准
        }

获取身份证地址

public static string getAddress(string cardId)
        {
            if (isCardId(cardId))
            {
                string index = cardId.Substring(0, 6);
                return areaInfo[index].ToString();
            }
            else
            {
                return null;
            }
        }

获取生日

public static string getBirthday(string cardId)
        {
            if (isCardId(cardId))
            {
                if (isCardId18(cardId))
                {
                    return cardId.Substring(6, 8).Insert(4, "-").Insert(7, "-");
                }
                else
                {
                    return ("19" + cardId.Substring(6, 6)).Insert(4, "-").Insert(7, "-");
                }
            }
            else
            {
                return null;
            }
        }

获取性别

public static string getSex(string cardId)
        {
            if (isCardId(cardId))
            {
                return Convert.ToInt16(cardId.Substring(16, 1)) % 2 == 0 ? "女" : "男";
            }
            else
            {
                return null;
            }
        }

根据出生日期，计算精确的年龄

public static int GetAge(string birthDay)
        {
            DateTime birthDate = DateTime.Parse(birthDay);
            DateTime nowDateTime = DateTime.Now;
            int age = nowDateTime.Year - birthDate.Year;
            //再考虑月、天的因素
            if (nowDateTime.Month < birthDate.Month || (nowDateTime.Month 
            == birthDate.Month && nowDateTime.Day < birthDate.Day))
            {
                age--;
            }
            return age;
        }