/// <summary>
/// 验证身份证是否合法
/// </summary>
/// <param name="idCard">要验证的身份证</param>    
public static bool IsIdCard(string idCard)
{
  //如果为空，认为验证合格
  if (IsNullOrEmpty(idCard))
  {
 return true;
  }
  //清除要验证字符串中的空格
  idCard = idCard.Trim();
  //模式字符串
  StringBuilder pattern = new StringBuilder();
  pattern.Append(@"^(11|12|13|14|15|21|22|23|31|32|33|34|35|36|37|41|42|43|44|45|46|");
  pattern.Append(@"50|51|52|53|54|61|62|63|64|65|71|81|82|91)");
  pattern.Append(@"(\d{13}|\d{15}[\dx])$");
  //验证
  return RegexHelper.IsMatch(idCard, pattern.ToString());
}