C#检查身份证号码

public static class Util
{
// <summary>
/// 检查身份证信息是否合法
/// 2010-10-13 jorln
/// </summary>
/// <param name="num">身份证号</param>
/// <param name="sex">性别</param>
/// <returns></returns>
public static bool CheckIdentity(string num, string sex)
{
bool isIden = false;
if (Convert.ToInt32(num.Substring(6, 4)) > 1850 && Convert.ToInt32(num.Substring(6, 4)) < 2010 && Convert.ToInt32(num.Substring(10, 2)) <= 12 && Convert.ToInt32(num.Substring(12, 2)) <= 31)
{
if (num.Substring(10, 2) == "02" && Convert.ToInt32(num.Substring(10, 2)) > 29)
return isIden;
if ((Convert.ToInt32(num.Substring(16, 1)) % 2 == 0 && sex == "女") || (Convert.ToInt32(num.Substring(16, 1)) % 2 != 0 && sex == "男"))
{
int count = 0;
int[] iden = { 7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2, };
for (int i = 0; i < iden.Length; i++)
{
count += Convert.ToInt32(num.Substring(i, 1)) * iden[i];
}
int cc = count % 11;
char num18 = cc == 0 ? '1' : (cc == 1 ? '2' : (cc == 2 ? 'X' : (cc == 3 ? '9' : (cc == 4 ? '8' : (cc == 5 ? '7' : (cc == 6 ? '6' : (cc == 7 ? '5' : (cc == 8 ? '4' : (cc == 9 ? '3' : '2')))))))));
isIden = num.Substring(17, 1).ToUpper() == num18.ToString() ? true : false;

}
}
return isIden;
}
}