身份证号验证

/// <summary>
/// 身份证验证
/// </summary>
/// <param name="cid"></param>
/// <returns></returns>
public static bool CheckIDCard(string cid)
{
string[] aCity = new string[] { null, null, null, null, null, null, null, null, null, null, null, "北京", "天津", "河北", "山西", "内蒙古", null, null, null, null, null, "辽宁", "吉林", "黑龙江", null, null, null, null, null, null, null, "上海", "江苏", "浙江", "安微", "福建", "江西", "山东", null, null, null, "河南", "湖北", "湖南", "广东", "广西", "海南", null, null, null, "重庆", "四川", "贵州", "云南", "西藏", null, null, null, null, null, null, "陝西", "甘肃", "青海", "宁夏", "新疆", null, null, null, null, null, "台湾", null, null, null, null, null, null, null, null, null, "香港", "澳门", null, null, null, null, null, null, null, null, "国外" };
double iSum = 0;
System.Text.RegularExpressions.Regex rg = new System.Text.RegularExpressions.Regex(@"^\d{17}(\d|x)$");
System.Text.RegularExpressions.Match mc = rg.Match(cid);
if (!mc.Success)
{
return false;
}
cid = cid.ToLower();
cid = cid.Replace("x", "a");
if (aCity[int.Parse(cid.Substring(0, 2))] == null)
{
return false;
}
try
{
DateTime.Parse(cid.Substring(6, 4) + "-" + cid.Substring(10, 2) + "-" + cid.Substring(12, 2));
}
catch
{
return false;
}
for (int i = 17; i >= 0; i--)
{
iSum += (System.Math.Pow(2, i) % 11) * int.Parse(cid[17 - i].ToString(), System.Globalization.NumberStyles.HexNumber);
}
if (iSum % 11 != 1)
{
return false;
}
return true;
}