常用正则表达式 c#

  /// <summary>
        /// 是否手机号
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static bool isPhone(string str)
        {
            return System.Text.RegularExpressions.Regex.IsMatch(str, @"^[1]+[3,5,8]+\d{9}");
        }

        /// <summary>
        /// 是否为xxxx-xx-xx的时间格式
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static bool isDateTime(string str)
        {
            return System.Text.RegularExpressions.Regex.IsMatch(str, @"\d{4}-(1[0-2]|[0]?\d)-(3[01]|[0-2]?\d)");
        }
        /// <summary>
        /// 是否为4个汉字以内（含4个）的名字
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static bool isName(string str)
        {
            return System.Text.RegularExpressions.Regex.IsMatch(str, @"^[\u4E00-\u9FA5]{0,4}$");
        }

        /// <summary>
        /// 验证身份号证
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static bool IsIDcard(string str)
        {
            return System.Text.RegularExpressions.Regex.IsMatch(str, @"(^\d{18}$)|(^\d{15}$)");
        }

        /// <summary>
        /// 验证是否为邮政编码
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>

        public static bool IsPostalcode(string str)
        {
            return System.Text.RegularExpressions.Regex.IsMatch(str, @"^\d{6}$");
        }
        /// <summary>
        /// 验证是否为邮箱
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static bool isEmail(string str)
        {
            return System.Text.RegularExpressions.Regex.IsMatch(str, @"\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*");
        }
        /// <summary>
        /// 验证是否是纯数字和字母组合
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static bool IsNumAndWord(string str){

            return System.Text.RegularExpressions.Regex.IsMatch(str, @"^(-?\d+)(\.\d+)$");

        }
        /// <summary>
        /// 验证是否是纯字母
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static bool IsWord(string str)
        {
            return System.Text.RegularExpressions.Regex.IsMatch(str, @"^[a-zA-Z]+$");
        }
       /// <summary>
       /// 验证六位数以上数字，符号，字母任意两种混合的密码验证策略
       /// </summary>
       /// <param name="str"></param>
       /// <returns></returns>
        public static bool ishunhe(string str)
        {
            return System.Text.RegularExpressions.Regex.IsMatch(str, @"^[a ^(?![0-9]+$)(?![a-zA-Z]+$)(?!([^(0-9a-zA-Z)]|[\(\)])+$)([^(0-9a-zA-Z)]|[\(\)]|[a-zA-Z]|[0-9]){6,}$");
        }
        /// <summary>
        /// 判断是否为双精度
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static bool isDouble(string str)
        {
            return System.Text.RegularExpressions.Regex.IsMatch(str, @"^[-\+]?\d+(\.\d+)$");
        }

　　　　　　

/// <summary>
/// 金额大小写转换
/// </summary>
/// <param name="number"></param>
/// <returns></returns>
public static String ConvertToChinese(Decimal number)
{
var s = number.ToString("#L#E#D#C#K#E#D#C#J#E#D#C#I#E#D#C#H#E#D#C#G#E#D#C#F#E#D#C#.0B0A");
var d = Regex.Replace(s, @"((?<=-|^)[^1-9]*)|((?'z'0)[0A-E]*((?=[1-9])|(?'-z'(?=[F-L\.]|$))))|((?'b'[F-L])(?'z'0)[0A-L]*((?=[1-9])|(?'-z'(?=[\.]|$))))", "${b}${z}");
var r = Regex.Replace(d, ".", m => "负元空零壹贰叁肆伍陆柒捌玖空空空空空空空分角拾佰仟万亿兆京垓秭穰"[m.Value[0] - '-'].ToString());
return r;
}

所有的正则都是在网上找的，这里做了一个总结，有所错误请指正。