In the System.Text.RegularExpression namespace, there are regular expression methods.

using System.Collections.Generic;

using System.Text; using System.Text.RegularExpressions;

namespace RegexDemo { class Program { static void Main(string[] args) { Regex regex = new Regex(“China”, RegexOptions.IgnoreCase); // use the Match method. string source = “China is my mother,My mother is china!”; Match m = regex.Match(source); if (m.Success) { Console.WriteLine (” find the first match ”); } Console.WriteLine(new string(’-‘,9)); // the following sample demonstrates matching using the Matches method MatchCollection matches=regex.Matches(source); foreach(Match s in matches) { if(s.Success) Console.WriteLine(” found a match ”); } Console.ReadLine(); } } } [/code]

using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;
namespace URLRegex
{
    class Program
    {
        static void Main(string[] args)
        {
            string Pattern = @"^(http|https|ftp)\://[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(:[a-zA-Z0-9]*)?/?([a-zA-Z0-9\-\._\?\,\'/\\\+&$%\$#\=~])*$";
            Regex r = new Regex(Pattern);
            string source = "https://www.ofstack.com";
            Match m = r.Match(source);
            if (m.Success)
            {
                Console.WriteLine("URL Authentication is successful !");
            }
            else
            {
                Console.WriteLine("URL Validation fails !");
            }
            Console.ReadLine();
        }
    }
}