// C# Extension Method

// Doc: https://csharp-extension.com/en/method/1002717/object-issubclassof

​

// @nuget: Z.ExtensionMethods

using System;

public class Program

{

    public class Class1 { }

    public class DerivedC1 : Class1 { }

    public static void Main()

    {

        DerivedC1 obj = new DerivedC1();

        //C# Extension Method: Object - IsSubclassOf

        Console.WriteLine("DerivedC1 subclass of Class1: {0}", obj.IsSubclassOf(typeof(Class1)));

    }

}