How do I validate a string Guid in C#.NET?

using System;
using System.Text.RegularExpressions;
 
public static class GuidUtility
{
    public static bool IsGuid( string guid )
    {
        if ( !string.IsNullOrEmpty( guid ) )
        {
            Regex regex = new Regex( @"^(\{{0,1}([0-9a-fA-F]){8}-([0-9a-fA-F]){4}-([0-9a-fA-F]){4}-([0-9a-fA-F]){4}-([0-9a-fA-F]){12}\}{0,1})$" );
 
            return regex.IsMatch( guid );
        }
 
        return false;
    }
}

How do I remove the port number from a URL in C#.NET?

Regular Expression:

:{1}\d*

Using C#.NET, the above regular expression can be applied to a URL to strip the port number (along with ":"):

Regex regex = new Regex( @":{1}\d{1,}" );
string url = regex.Replace( "http://andrewgunn.blogspot.com:81/", string.Empty );