MultipleClassInheritanceUsingInterfaces.cs

using System;

interface IA
{
    void AMethod(); //declare method
                    //method implemented in class A
}

public class A : IA //inherit from interface A
{
    public void AMethod()
    {
        Console.WriteLine("AMethod called");
    }
}

interface IB
{
    void BMethod(); //declare method
                    //method implemented in class B
}

public class B : IB //inherit from interface B
{
    public void BMethod()
    {
        Console.WriteLine("BMethod called");
    }
}

public class AB : IA, IB //inherit from interface A and B
{
    private A a = new A(); //instantiate object A with reference of 'a'
    private B b = new B(); //instantiate object B with reference of 'b'

    public void AMethod()
    {
        a.AMethod(); //invoke method from class A
    }

    public void BMethod()
    {
        b.BMethod(); //invoke method from class B
    }
}


public class Program
{
    public static void Main()
    {
        AB ab = new AB(); //instantiate object AB with reference of 'ab'
        
        //now it is possible to access both methods, from seperate classes because each class inherits from multiple interfaces
        ab.AMethod(); 
        ab.BMethod(); 

        Console.ReadKey();
    }
}