C# 验证18位身份证号

public string CheckIDCard18(string idNo)
        {
            long n = 0;
            if (idNo.Trim().Length != 18)
            {
                return "N";
            }
            if (long.TryParse(idNo.Remove(17), out n) == false || n < Math.Pow(10, 16) || long.TryParse(idNo.Replace('x', '0').Replace('X', '0'), out n) == false)
            {
                return "N";
            }
            string address = "11x22x35x44x53x12x23x36x45x54x13x31x37x46x61x14x32x41x50x62x15x33x42x51x63x21x34x43x52x64x65x71x81x82x91";
            if (address.IndexOf(idNo.Remove(2)) == -1)
            {
                return "N";
            }
            string birth = idNo.Substring(6, 8).Insert(6, "-").Insert(4, "-");
            DateTime time = new DateTime();
            if (DateTime.TryParse(birth, out time) == false)
            {
                return "N";
            }
            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 = idNo.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] != idNo.Substring(17, 1).ToLower())
            {
                return "N";
            }
            return "Y";
        }