using System;

public class Program

{

    public static void Main()

    {

        var evtType = typeof(MyEvent);

        var intType = typeof(ICustom);

        Console.WriteLine("MyEvent IsAssignableFrom ICustom? " + evtType.IsAssignableFrom(intType));

        Console.WriteLine("ICustom IsAssignableFrom MyEvent? " + intType.IsAssignableFrom(evtType));

    }

}

​

public interface ICustom

{

}

​

public class MyEvent : ICustom

{

}