public abstract Guid GUID { get; }

Implements

A GUID is associated with a type using the GuidAttribute attribute.

The following example creates the class MyClass1 with a public method, creates a Type object corresponding to MyClass1, and gets the Guid structure using the GUID property of the Type class.

using System;

class MyGetTypeFromCLSID
{
    public class MyClass1
    {
        public void MyMethod1()
        {
        }
    }
    public static void Main()
    {
        // Get the type corresponding to the class MyClass.
        Type myType = typeof(MyClass1);
        // Get the object of the Guid.
        Guid myGuid =(Guid) myType.GUID;
        Console.WriteLine("The name of the class is "+myType.ToString());
        Console.WriteLine("The ClassId of MyClass is "+myType.GUID);				
    }
}

.NET Framework

.NET Framework Client Profile

Windows 8 Release Preview, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 SP2, Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference