ExplicitInterfaceImplementation.cs

using System;

/* Explicit Interface Implementation
 * 
 * When you are explicitly implementing an interface member, you are not allowed to use an access modifier
 * 
 * You have to use the interface name dot MethodName, ex. IInterface1.InterfaceMethod();
 * 
 * When a class explicitly implements an interface member, the interface member can no longer be accessed through a
 * class reference variable, but instead can only be accessed via the interface reference variable
 * 
 */

interface I1
{
    void InterfaceMethod();
}

interface I2
{
    void InterfaceMethod();
}

public class Program : I1, I2 
{
    void I1.InterfaceMethod() //explicit interface member implementation 
    {
        Console.WriteLine("I1 interface InterfaceMethod called");
    }

    void I2.InterfaceMethod() //explicit interface member implementation
    {
        Console.WriteLine("I2 interface InterfaceMethod called");
    }

    public static void Main()
    {
        //invocation using typecasting
        var P = new Program();
        ((I1)P).InterfaceMethod(); //access by typecasting object(P) reference variable to be of type I1
        ((I2)P).InterfaceMethod(); //access by typecasting object(P) reference variable to be of type I2

        Console.WriteLine("-------------------");

        //invocation by creating an object reference variable of interface type
        I1 i1 = new Program();
        I2 i2 = new Program();

        i1.InterfaceMethod();
        i2.InterfaceMethod();


        //cannot invoke P.InterfaceMethod() when using explicit interface implementation

        Console.ReadKey();
    }
}