using System;

namespace Test {

    public interface ISomeInterface1 {

        void SomeMethod();

        int SomeProperty {get; set;}

        event EventHandler SomeEvent;

        int this[string index] {get; set;}

    }

    public class ExplicitImplemantion : ISomeInterface1 {

        private EventHandler someEventVar;

        void ISomeInterface1.SomeMethod(){

            //this method belongs to teh interface only 

            // do some stuff here

            Console.WriteLine("This is method belongs to interface");

        }

        public void SomeMethod(){

            // do some stuff here

            // this method belong to teh class only

            Console.WriteLine("This is method belongs to class");

        }

        int ISomeInterface1.SomeProperty {get; set;}

        event EventHandler ISomeInterface1.SomeEvent {

            add { someEventVar += value;  } 

            remove {someEventVar -= value; }

        }

        int ISomeInterface1.this[string index] {

            get{

                return 0;

            }

            set{

                // do some assignation to a collection basign on index passed

                // arr[index] = value;

            }

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            ExplicitImplemantion obj = new ExplicitImplemantion();

            ISomeInterface1 interfaceObj = obj as ISomeInterface1;

            obj.SomeMethod();        // this is not allowed operation

            interfaceObj.SomeMethod(); // this is allowed operation

            //int val1 = obj.SomeProperty;        // this is not allowed operation

            int val2 = interfaceObj.SomeProperty; // this is allowed operation

            //obj.SomeEvent += someHandler;        // this is not allowed operation

            //interfaceObj.SomeEvent += EventHandler; // this is allowed operation

            //int val3 = obj["someKey"];        // this is not allowed operation

            int val4 = interfaceObj["someKey"]; // this is allowed operation

        }

    }

}