StringExtensions.cs

public static class StringExtensions
    {
        public static bool IsDate(this string value)
        {
            if (DateTime.TryParse(value, out DateTime Temp) == true)
                return true;
            else
                return false;
        }

        /// <summary>
        /// Returns true if input contains all numbers or any currency format
        /// </summary>
        /// <param name="value"></param>
        /// <returns></returns>
        public static bool IsNumeric(this string value)
        {
            string pattern = @"^\S{0,3}(kr\.)?\s*(((\d{1,3})([,\.]\d{3})*)|(\d+))(.\d+)?\s*\$?((Kč)|(Ft)|(.د.م.)|(zł)|(p.)|(﷼)|(฿)|(₺)|(₫))?$";
            RegexOptions options = RegexOptions.Multiline;
            
            return Regex.IsMatch(value, pattern, options);
        }
    }