About Polymorphism

[Jongmin]

Dear Everybody,

In the following codesnippet, rceceiver gets different
requests of which sender knows interfaces.
I want to do diffent job based on concrete class in
receiver.

How to implement this pattern?

Thanks,
// ----- Code -----------------------
using System;

namespace TestConsole
{
class Apps
{
[STAThread]
static void Main(string[] args)
{
Receiver receiver = new Receiver();
Sender sender = new Sender(receiver);

RequestSquare requestSquare = new RequestSquare
();
requestSquare.Op1 = 10;
sender.Send(requestSquare);

RequestTimes requestTimes = new RequestTimes();
requestTimes.Op1 = 30;
requestTimes.Times = 3;

sender.Send(requestSquare);
sender.Send(requestTimes);
}
}

public class Sender
{
private IReceiver _Receiver = null;
public Sender(IReceiver receiver)
{
_Receiver = receiver;
}

public void Send(IRequest request)
{
_Receiver.Receive(request);
}
}

public class Receiver : IReceiver
{
public void Receive(IRequest request)
{
if (request is RequestSquare)
{
Receive((RequestSquare)request);
return;
}
if (request is RequestTimes)
{
Receive((RequestTimes)request);
return;
}
}

public void Receive(RequestSquare request)
{
Console.WriteLine(request.Op1*request.Op1);
}

public void Receive(RequestTimes request)
{
Console.WriteLine(request.Op1*request.Times);
}

}

public interface IReceiver
{
void Receive(IRequest request);
}

public class RequestSquare : IRequest
{
private int _Op1;
public int Op1
{
get { return _Op1;}
set {_Op1 = value;}
}
}

public class RequestTimes : IRequest
{
public int Times;
private int _Op1;
public int Op1
{
get { return _Op1;}
set {_Op1 = value;}
}
}

public interface IRequest
{
int Op1
{
get; set;
}
}
}