Software development

// Command pattern -- Structural example

using System;

namespace DoFactory.GangOfFour.Command.Structural
{

// MainApp test applicatio

class MainApp
{
static void Main()
{
// Create receiver, command, and invoker
Receiver receiver = new Receiver();
Command command = new ConcreteCommand(receiver);
Invoker invoker = new Invoker();

// Set and execute command
invoker.SetCommand(command);
invoker.ExecuteCommand();

// Wait for user
Console.Read();
}
}

// "Command"

abstract class Command
{
protected Receiver receiver;

// Constructor
public Command(Receiver receiver)
{
this.receiver = receiver;
}

public abstract void Execute();
}

// "ConcreteCommand"

class ConcreteCommand : Command
{
// Constructor
public ConcreteCommand(Receiver receiver) :
base(receiver)
{
}

public override void Execute()
{
receiver.Action();
}
}

// "Receiver"

class Receiver
{
public void Action()
{
Console.WriteLine("Called Receiver.Action()");
}
}

// "Invoker"

class Invoker
{
private Command command;

public void SetCommand(Command command)
{
this.command = command;
}

public void ExecuteCommand()
{
command.Execute();
}
}
}

Output expected:

Called Receiver.Action()